DE2437890A1 - THIAFURANE AND FURANTHIOLS, METHOD FOR THEIR PRODUCTION AND THEIR USE AS A FLAVOR - Google Patents

Description

25 580 n / wa

INTERNATIONAL FLAVORS & FRAGRANCES INC., NEW YORK, N.Y. / UNITED STATES

Thiafurans and furanthiols, processes for their preparation and their use as Flavoring agents

The invention relates to certain 3-thiafurans and 3-mercaptofurans, a process for their economical production in good yield and for the application of such Compounds for changing the organoleptic properties of food by adding at least

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a 3-thiafuran on such materials.

The invention relates in particular to thiafurans of the formula:

wherein R 1 represents a straight-chain or branched alkyl or alkenyl group with 1 to 7 carbon atoms or R _{g represents} furyl, thienyl, toluyl, phenylethenyl or phenyl and each of R ₁ , Rp and R. identically or differently has hydrogen or an alkyl group C ₁ to C. means. The invention also relates to the use of such thiafurans as flavorings or seasonings for foods and to a process for the production of these furans and other thiafurans of the formula:

where R _{3 is} hydrogen, alkyl, acyl or aroyl, and R ₁ , R 1 and R are the same or different and are each hydrogen or C ₁ to C-alkyl.

Preferred 3-thiafurans useful as flavoring agents in the invention are as follows:

- "3 _

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3-thioacetylfuran

2,5-dimethyl-3-thioacetylfuran 2-methyl-3-thioacetylfuran 2,5-dimethyl-4-ethyl-3-thioacetylfuran 2-methyl-3-thioiobutyrylfuran 2,5-dimethyl-3-thioisobutyrylfuran 2,5-dimethyl-3-thio- (2-ethylbutyryl) furan 2-methyl-3-thio- (2-ethylbutyryl) furan 2,5-dimethyl-3-thio- (2-methylbutyryl) furan 2-methyl-3-thio- (2-methylbutyryl) furan 2, S-dimethyl-S-thioisovalerylfuran 2-dimethyl 1-3-thioisovaleryl furan 2-methyl-3 (2-thiofuroyl) furan 2,5-dimethyl-3 (2-thiofuroyl) furan 2-methyl-3-thiooctanoylfuran 2,5-dimethyl-3-thiooctanoylfuran 2,5-dimethyl-3-thiobenzoylfuran 2,5-dimethyl 1-3-thiopropionyl furan 2-methyl 1-3-thiopivaloylfuran 2,5-dimethyl 1-3-thiopivaloylfuran 2,5-dimethyl-3-thiohexanoylfuran 2-propyl-3-thioacetylfuran 2,5-dimethyl-3-thio (2-methyl-2-pentenoyl) furan 2,5-dimethyl-3-thiotoluoylfuran 2, S-dimethyl-S-thiocinnamoylfuran 2,5-dimethyl-3-thio (2-methyl-2-pentenoyl) furan

The compounds according to the invention and other compounds, which are useful or usable for the production of food flavors are produced by a process, which includes the steps:

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(i) Provision of a 2-en-1,4-dione of the structure:

Λρ of

(ii) intimate admixture of the 2-ene-1,4-dione with a thioacid of the formula R ₃ SH (where R _{3 can be} alkyl, aroyl or acyl), thereby creating a substituted or unsubstituted 1,4-dione of the structure :

R ₄

(iii) Cyclization of the 2-thia substituted 1,4-dione to Formation of a substituted or unsubstituted 3-ThLafuran of the formula:

(iv) optionally, but only when R-, acyl or Aroyl represents hydrolysis of the 3-thiafuran to form a 3-mercaptofuran of the structure:

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SH

R ₁ ^ ₂

(ν) Implementation of the 3-mereaptofuran thus formed with an acylating or aroylating agent, whereby a new acyl- or aroyl-3-thiafuran is formed which has the structure:

R ₁ « ₂

wherein each of R .., R "and R., identically or differently, denote hydrogen or lower _{alkyl, wherein R 0 represents} alkyl, acyl or aroyl, and wherein R ₅ denotes acyl or aroyl different from R ₀ . R ₁ and R ~ can each denote hydrogen in the event that, in step (ii), the 2-ene-1,4-dione with the thioacid of the formula R ₀ SH in the presence of an organic base such as piperidine, pyridine, triethylamine , Quinoline or cL-picoline or a mixture thereof is mixed.

The 2-en-1,4-dione is obtained by reacting 2,5-dialkoxy-2,5-dialkyl-2,5-dihydrofuran with a weak acid hydrolyzing agent such as 1% aqueous acetic acid produced under reflux conditions. The resulting material if you think of 2,5-dimethoxy-2,5-dimethyl-2,5-dihydrofuran starts out, is cis-3-hexene-2,5-dione.

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The resulting 2-en-1,4-dione is then _{reacted with a thiol or a thioacid of the formula R 3} SH, in which R _{3 is} alkyl, acyl or aroyl.

Examples of such thiols and thioacids are:

Thicesetic acid

Thiopropionic acid thiobutyric acid

Thioisobutyric acid Thio-n-pentenoic acid thiocinnamic acid

Thiobenzoic acid

2-methyl-thiobenzoic acid 3-methyl-thiobenzoic acid 4-methyl-thiobenzoic acid 2,4-dimethyl-thiobenzoic acid Methy! Mercaptan

Ethyl mercaptan

n-propyl mercaptan isopropyl mercaptan n-butyl mercaptan Isobutyl mercaptan n-hexyl mercaptan n-octyl mercaptan n-Nonyl mercaptan Benzyl mercaptan

Thiophenol

p-tolyl mercaptan, m-tolyl mercaptan o-Tolyl mercaptan 3,5-dimethylthiobenzoic acid

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Regardless of whether an organic base is used in the reaction between the 2-en-1,4-dione and the thiol or the thioacid of the formula R 1 SH is used or not include suitable ones 2-en-1,4-diones the following:

Name of the connection

3-hexene-2,5-dione methyl methyl hydrogen 3-methyl-3-hexene-2,5-
dion methyl methyl methyl 3-methyl-3-heptene-2,5-
dion methyl ethyl methyl 3-ethyl-3-heptene-2,5-
dion methyl ethyl ethyl 4-ethyl-4-octene-3,6-
dion ethyl ethyl ethyl 3-propyl-3-heptene-2,5-
dion methyl ethyl Propyl 4-methyl-3-heptene-2,5-
dion - ethyl methyl methyl 4-methyl-4-octene-3,6-
dion ethyl ethyl methyl 4-methyl-4-nonene-3,6-
dion ethyl Propyl methyl 4-propyl-3-heptene-3,6-
dion ethyl methyl Propyl 5-methyl-5-decene-4,7-
dion Propyl Propyl methyl 5-methyl-4-nonene-3,6-
dion Propyl ethyl methyl 4-methyl-3-nonene-2,5-
dion Butyl methyl methyl 4-ethyl-3-nonene-2,5-
dion Butyl methyl ethyl

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3-methyl-3-nonene-2,5-dione

3-propyl-3-nonene-2,5-dione

3-butyl-3-hexene-2,5-dione

4-octene-3,6-dione

Methyl butyl

Methyl butyl

Methyl methyl

Ethyl ethyl

Methyl propyl

Butyl hydrogen

As indicated above, one or both radicals R ₁ and R _{9 can represent} hydrogen if an organic

I ^ *

see base present in the reaction with the thioacid. Thus, in addition to the compounds given above, the following materials are suitable reactants with the thiol or thioacid R ₃ SH.

Name of the connection ^R 1 R ₂ R ₄ 2-butene-1,4-dial water
material water
material water
material 2-methyl-2-butene-1,4-
dial water
material water
material methyl 2-pentenal-4-one methyl water
material water
material 2-hexenal-4-one ethyl water
material water
material 3-methyl-2-hexenal-4-
on ethyl water
material methyl 2-methyl-2-pentenal
4-on water
material methyl water
material 2-methyl-2-heptenal
4-on water
material Propyl methyl 2-methyl-2-octenal
4-on water
material Butyl methyl

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Examples of organic bases that can be used are piperidine, pyridine, quinoline, triethylamine and s »- picoline. Instead of such organic bases can be radical initiators; such as benzoyl peroxide or azobisisobutyronitrile, can be applied. The reaction can be carried out in a solvent such as water or an ether such as Diethyl ether, or a hydrocarbon such as Benzene or hexane or cyclohexane. The reaction between the 2-ene-1,4-dione and the thiol or the thioacid can also be carried out without the use of a solvent. The reaction is under reflux conditions carried out, albeit temperatures ranging from 0 to 60 ° can vary, are suitable, and give economically justifiable yields. Examples of reaction products, 2-thia-substituted 1,4-diones, which are involved in the reaction of the 2-ene-1,4-diones with the thiols and thioacids of the formula R-.SH are as follows:

2-ene-1,4-dione
Reactant

R ^ SH-thiol or 2-thia substituted sodium acid reactant 1,4-dione reaction product

3-hexene-2,5-dione

3-methyl-3-hexene-2,5-dione

Thioacetic acid

Thiopropionic acid

3-methyl-3-hepten-thiobenzoic acid 2,5-dione

4-ethyl-4-octene-3,6-thioacetic acid dion

3-thioacetyl-2,5-hexanedione

3-thiopropionyl-4-methyl-hexane-2,5-dione

4-thiobenzoyl-4-methyl-heptane-3,6-dione

4-thioacetyl-5-ethyloctane-3,6-dione

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2-pentenal-4-one

3-ethyl-3-hepten-2,5-dione

3-propyl-3-hepten-2,5-dione

4-methyl-3-hepten-2,5-dione

2-butene-1,4-dial

2-methyl-2-butene-1,4-dial

4-oxo-2-heptenal

4-methyl-thio benzoic acid

Thiobenzoic acid

Buty! Mercaptan

o-Toy! mercaptan

Thioacetic acid

Buty! Mercaptan

Thioacetic acid

3- (4-methylthiobenzoyl) -2-pentanal-4-one

4-thiobenzoyl-5-ethyl-heptane-3,6-dione

4-butyl-thio-5-propyl heptane-3,6-dione

3- (o-Tolyl-thio) -4-methyl-heptane-2,5-dione

2-thioacetyl-butane-1,4-dial

2-butylthio-3-methyl-butane-1,4-dial

4-oxo-3-thio-hexanal

The above 2-thia substituted 1,4-diones are then cyclized to form substituted or unsubstituted 3-thiafurans according to the following reaction scheme:

where R ₁ and Rp are the same or different and each _{signifies hydrogen or C 1} -C. lower alkyl, where R 1 is alkyl, acyl or aroyl and R. signifies hydrogen or C ₁ -C. lower alkyl. The resulting 3-thiafurans (including the new compounds according to the invention) can be hydrolyzed as such because of their organoleptic properties * or, in the case that R_ denotes acyl or aroyl, and then

^ be used

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again acylated or re-aroylated to produce other acyl-thia- or aroyl-thia-substituted furans (others to form new compounds according to the invention), which still others have organoleptic properties useful for flavoring foods.

The reaction by which the 2-thia-substituted 1,4-dione * is cyclized in the presence of a cyclizing agent, preferably an enol ester such as isopropenyl acetate and a catalyst such as concentrated Sulfuric acid, zinc chloride, boron trifluoride, aluminum trichloride and para-toluenesulfonic acid, any of the foregoing Compounds is an acid catalyst. The ratio of isopropenyl acetate to 2-thia substituted is preferably 1,4-dione 4 to 5: 1. The ratio of acid catalyst to isopropenyl acetate is from 0.001 to 0.05 (molar ratio) . The cyclization reaction can take place at temperatures between 25 to 150 ° C and preferably at reflux temperatures Atmospheric pressure (96 ° C) can be carried out. Even higher reflux temperatures can be used when the pressure is above atmospheric pressure. In addition, acetic anhydride can be used as a cyclizing agent instead of isopropenyl acetate or propionic anhydride can be used. The ratios of acetic anhydride or propionic anhydride to 2-thia substituted 1,4-dione are preferably 4 to 5: 1 (MoI ratioJL

When the resulting 3-thiafuran as a food additive is to be used, the reaction product is purified by suitable extraction and distillation techniques. Thus, the following 3-thiafurans according to the invention,

* is effected

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made in this way, useful organoleptic Properties on which their application as food flavorings as shown in the following table for illustrative purposes:

2-thia substituted
1,4-dione reactant

3-thia-furan reaction product

Taste and flavor properties of the 3-thiofuran reaction product

3-thioacetyl-2,5-hexanedione

3-thiobenzoyl-2,5-hexanedione

4-OXO-3-thio-hexanal

2,5-dimethyl-3-thioacetylfuran

2,5-dimethyl-3-thiobenzoyl furan

2-propyl-3-thioacetylfuran

Toasted meat and sauce-like flavor; roasted meat flavor 2 ppm (threshold 0.05 ppm). Sweet floral scent of radishes.

Cooked chicken-like flavor with a touch of roasted meat; fatter flower-like egg taste at 2 ppm (threshold value 0.1 ppm)

Sweet, leek, roasted aromas and flavors at 0.25 ppm

In addition, other 3-thiafurans produced in this way have useful organoleptic properties on showing their application as food flavorings enable or flavor materials, e.g. of 3-propylthia-2,5-dimethylfuran, whose precursor is 3-propylthia-2,5-hexanedione. 3-propyl-thia-2,5-dimethylfuran has

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exhibited a roasted meat flavor and a roasted meat flavor at 5 ppm.

An optional additional step is the hydrolysis of the 3-thiafuran (when R- is acyl or aroyl) Formation of 3-mercaptofuran of the structure:

The hydrolysis reaction is carried out in the presence of a strong aqueous base, e.g. sodium hydroxide, potassium hydroxide, sodium carbonate, Lithium carbonate, potassium carbonate and lithium hydroxide. The molar ratio of base to 3-thiafuran is preferably 1: 1, but can be as high as 3: 1 or as low as 0.01: 1. Additionally In addition to aqueous base solutions alone, mixtures of alcohol (e.g. methanol and ethanol) and water can be used as solvents can be used in the hydrolysis reaction. The hydrolysis temperature can range from room temperature to the reflux temperature vary. If the basic solution is an alcoholic solution (essentially pure alcoholic solution) the alkali metal thiofuran can be formed.

The reacylation of the 3-furanethiol to obtain more Acylthiofurans, or aroylthiofurans, are made by reaction

the appropriate acyl or aroyl halide with the 3-furan thiol in the presence of a suitable solvent such as diethyl ether, tetrahydrofuran or cyclohexane and in the presence of

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preferably carried out a strong organic base such as pyridine or CM-picoline. Thus the following table gives suggests several compounds which can be conveniently formed and a large number of organoleptic ones Have properties that lead to a wide range of uses for flavoring and seasoning purposes:

Name of the compound organ pleptic properties

2-methyl-3-thio-isobutyrylfuran

2,5-dimethyl-3-thioisobutyrylfuran

2,5-dimethyl-3-thioisovalerylfuran

2-methyl-3-thio-isovalerylfuran

2-methyl-3 (2-thiofuroyl) furan

2,5-dimethyl-3 (2-thiofuroyl) furan Sweet, fruity, anise-like and liver-like flavors; anise-like sweet fruity roasted meat taste at a concentration of 0.05 ppm.

Meaty, ham and vegetable flavor; ham-like, meaty vegetable-nut taste at a concentration of 0.1 ppm.

Creamy, cocoa-like sweet aroma. Creamy green cocoa powder taste at a concentration of 0.1 ppm.

Green, fleshy, vegetable-like aroma. Greener, more meaty vegetable-like HVP-like taste at a concentration of 0.1 ppm.

HVP-like, meaty aroma; HVP-like, liver-like meaty Taste at a concentration of 0.02 ppm.

HVP-like, meaty aroma. HVP-like meaty taste at 0.1 ppm.

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2-Methy1-3-thio-octanoyl-furan

2,5-dimethyl 1-3-thiooc tanoyl-furan

2,5-dimethyl-3-thiobenzoylfuran

2-Methy1-3-thio-pivaloyl furan

2,5-dimethyl-3-thiopivaloylfuran

2,5-dimethyl-3-thiohexanoylfuran

2,5-dimethyl-3-thiocinnamoylfuran

2,5-dimethyl-3-thio- (m-toluoyl) furan

2,5-dimethyl 1-3-thio- (2-ethylbutyryl) -furan

Fleshy, sour, floral aroma; meaty, sour, floral, HVP-like taste a concentration of 0.1 ppm.

Meaty broth flavor; meaty nut-like broth-like aroma with an HVP aftertaste at a concentration of 0.1 ppm.

Cooked chicken-like, meat-like toasted aroma; floral greasy taste at 2ppm (0.1ppm threshold).

Sweet, roasted meat flavor; vegetable-like roasted meat flavor at a concentration of 0.1 ppm.

Sweet meaty chicken-like flavor; sulphurous meatier Taste at 0.5 ppm.

Meaty, green, creamy aroma; meatier, greener, creamier Nut-like taste at 0.5 ppm (0.1 ppm threshold).

Fleshy, brown sugar ·, green Walnut flavor; meat-like, gummy, sweet walnut taste at a concentration of 2 ppm.

Sulphurous, roasted meat and liver flavor; meatier, greener roasted, sulphurous fresh meat-liver-walnut kernel flavor 1 ppm.

heavy toasted aroma and sweet nutty roasted taste at 0.1 ppm. At 0.2 ppm, sweet toasted hazelnut aroma and taste. At 0.5 ppm a sweet mouthfeel, carob-like Notes and hydrolyzed vegetable protein aroma and taste with a bloody, meaty, lingering Aftertaste,

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2-methyl-3-thio- (2-ethylbutyryl) furan

2,5-dimethyl-3-thio (2-methylbutyryl) furan

2-methyl-3-thio (2-methylbutyryl) furan

2,5-dimethyl-3-thio- (2-methyl-2-pentanoyl) furan

At 0.1 ppm sweet meat, nutty, earthy, meaty, hydrolyzed Vegetable protein, meat extract aroma and taste.

At 0.05 ppm, meaty, toasted, sweet aroma and taste. At 0.1 ppm sweet roasted aroma and taste.

At 0.1 ppm sweet, roasted aroma and taste.

Meaty, sweet, HVP, creamy flavor; sweet roasted meat, gummy taste at 0.1 ppm.

The 3-thiafuran derivatives and their mixtures according to the invention can be used to change, vary, amplify, modify, promote or otherwise improve the organoleptic Properties, including taste and / or aroma, are applied to a wide variety of materials that are ingested, consumed or otherwise sensed organoleptically.

The term "changed" in its various forms here means the delivery or conferment of a flavor character or a flavor note to an otherwise mild, relative one tasteless substance or the enhancement of a present taste characteristic if the natural taste is still unsatisfactory in a certain direction, or the addition of the present taste or aroma impression Modification of the organoleptic character. The materials that are so altered are generally referred to herein as Called consumer materials.

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Such 3-thiafuran derivatives can thus be used in flavorings. Flavors mean here those that ein.Teil contribute to the overall taste impression in that they have a natural or artificial taste complement or enhance a material, as well as "those which essentially have the entire taste and taste of a consumer good / or give flavor character.

As used herein, the term "food" includes both solid and liquid ingestible materials for humans and animals, but these materials are normally not necessarily of nutritional value. Consequently the foods include meat, sauces, soups, fast food, Malt and other alcoholic or non-alcoholic beverages, milk and dairy products, nut butters such as peanut butter and others, seafood including fish, crustaceans, molusks and the like, sweets, Breakfast foods, baked goods, vegetables, grains, soft drinks, "snack" foods, dog and cat foods, other animal food products and the like.

If the 3-thaifuran derivatives according to the invention in a Food flavorings can be applied with conventional flavoring materials or adjuvants be combined. Such co-ingredients or flavor aids are known and are for such use has been described in detail in the literature. Apart from the requirement that any such auxiliary material must be suitable for consumption and must therefore not be toxic or otherwise harmful, conventional

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Materials are used which generally other flavor materials, Vehicles, stabilizers, thickeners, surfactants, conditioning agents and flavor enhancers include,

Examples of preferred co-flavoring aids are:

Methylthiazole alcohol (4-methyl-5-betahydroxyethyl thiazole);

2-methyl-butanethiol; 4-mercapto-2-butanone; 3-mercapto-4-pentanone; 1-mercapto-2-propanone; Benzaldehyde;

Furfural;

Furfuryl alcohol; 2-mercapto propionic acid; 2-pentene;

Alkylpyrazine; Methylpyrazine 2-ethyl 1-3-methylpyrazine; Tetramethylpyraz in; Polysulfides;

Dipropyl disulfide; Methylbenzyl disulfide; Alkylthiophene; 2-butylthiophene; 2,3-dimethylthiophene, 5-methylfurfural; Acetylfuran;

2,4-decadienal; Guiacol;

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Phenylacetaldehyde;

^ -Decalactone;

d-limonene;

Acetoin;

Amyl acetate;

Maltol;

Ethyl butyrate;

Levulinic acid;

Piperonal;

Ethyl acetate;

n-octanal;

η-pentanal;

Hexanal;

Diacetyl;

Monosodium glutamate;

sulfur-containing amino acids;

Cysteine;

hydrolyzed vegetable or vegetable protein; hydrolyzed fish protein; and Tetramethylpyrazxn.

The 3-thiafuran derivatives or the materials in which they are incorporated can, as mentioned above, with one or more vehicles or carriers for their addition to the particular product. Vehicle can represent edible or otherwise suitable materials such as ethyl alcohol, propylene glycol, water and the like. Carriers include materials such as gum arabic, carrageenan, other gums, and the like. The 3-thiafuran compounds according to the invention can with the carriers

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introduced in a conventional manner such as spray drying, drum drying and the like will. Such carriers can also contain materials for the accumulation of the 3-thiafuran derivatives (and other flavor ingredients, if present) to create encapsulated products. If the wearer has a Is emulsion, the flavor composition can also emulsifiers, such as mono- and diglycerides of fatty acids and the like contain. These carriers or vehicles can be used to produce the desired physical shape of the mass.

The amount of 3-thiafuran derivatives or their mixtures used should be sufficient to give the product the desired To impart taste properties. On the other hand is the application of an excessive amount of the derivative Not only is it wasteful and uneconomical, but in some cases too much can spoil the taste or unbalance the other organoleptic properties of the product consumed. The applied Amount will vary on the end food, the amount and type of that originally present in the food Taste, the further process or treatment stages to which the food is subjected, regional and other preference factors, the type of storage, if any, to which the product will be subjected and the treatment before consumption, such as baking, roasting and the like, to which the product is subjected by the end user will. Thus, the terms "effective amount" and "sufficient amount" are intended to be used in connection with the invention to change the taste of the food in terms of quantity suitable mean.

dependent on

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Accordingly, it is preferred that the final weights have from about 0.02 parts / million (ppm) to about 250 ppm of the 3-thiafuran derivative or der-derivatives included. In food materials in particular, it is desirable use about 0.05 ppm to 100 ppm for flavor enhancement and in certain preferred embodiments of the invention about 0.2 to 50 ppm of the derivatives are added, to give the final material favorable flavors.

The amount of 3-thiafuran material or materials according to the invention, which is to be used in flavorings or spice compositions, can be used over a wide range Range can be varied depending on the particular quality to be added to the food, Thus, amounts of one or more of the derivatives according to each Invention of about 2 ppm up to 80 or 90% of the total seasoning can be introduced into such masses. In general, it has been found desirable to have about 10 ppm to about 0.1% of the 3-thiafuran derivatives in such Bring in masses.

The following examples illustrate preferred embodiments of the invention, which are not intended to be limiting. All specified parts, quantities, proportions and Percentages in the following examples are provided unless they are otherwise indicated, indicated in weights.

Example I.

(Production of cis-3-hexene-2,5-dione)

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In a 1000 ml round bottom flask fitted with a condenser and magnetic stirrer is equipped, 2OO g of 2,5-dimethoxy-2,5-dimethyl-2,5-dihydrofuran and 200 ml of a 1% acetic acid aqueous solution. The resulting solution will heated to reflux, refluxed for 2 minutes, cooled to 25 ° C. with an ice bath and 625 ml added to a 2% sodium bicarbonate solution. The solution is saturated by adding 23 g of sodium chloride and extracted with methylene chloride (1 times 2OO ml and 3 times TOO ml), After drying over sodium sulfate and after removing the methylene chloride 142 g of crude cis-3-hexene-2,5-dione are obtained in vacuo obtained which, according to the GLC analysis, represent about 90% a product of the structure:

> 0

Example II

(Production of 3-thioacetyl-2,5-hexanedione)

In a 1000 ml round bottom flask, which is operated with a magnetic stirrer, Thermometer, addition funnel and reflux condenser, 142 g of crude cis-3-hexene-2,5-dione (from Example I), 380 ml of ether and 5 drops of piperidine entered. It becomes thioacetic acid (96.6 g) over 1 hour added. When about 1/8 of the thioacetic acid is added, the solution begins to reflux, which is continues until the rest of the addition. After the addition is complete

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the mixture is left to stand for 86 minutes. Then the ether is removed in vacuo (water separator) to obtain 23 5 g of raw material, which is about 91% Contains 3-thioacetyl-2,5-hexanedione. The distillation of a 134 g portion of the raw material gives 84.6 g 3-thioacetyl-2,5-hexanedione, which boils at 86 to 87 ° C at 0.5 torr. The NMR, IR and mass spectral analyzes confirm the following Structure:

Example III

(Production of 3-propylthio-2,5-hexanedione)

In a 500 ml flask fitted with a thermometer, addition funnel, If the reflux condenser and magnetic stirrer are fitted, 95 ml of ether and 1 drop of piperidine are then introduced the addition of n-propanethiol is started and with increasing addition more piperidine is added (total 33 Drops). After standing for 18 hours, the solution is successively saturated with 10% hydrochloric acid (2 times 7.5 ml) Sodium chloride solution (10 ml), 5% sodium bicarbonate solution and saturated sodium chloride solution (2 times 10 ml). The ether solution is dried over sodium sulfate and concentrated to give 51.4 g of a dark yellow oil. The GLC analysis shows that the material is essentially represents pure 3-thiopropyl-2,5-hexanedicn. the

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Mass spectral analysis shows the molecular ion 188 and then in decreasing order 43, 103, 41, 145, 71, 114 and 61 m / e units.

Example IV

(Production of 3 - mercapto-2,5-hexanedione)

To 150 ml of a 2% sodium hydroxide solution in one with a flask equipped with a stirrer, 10 g of 3-thioacetyl-2,5-hexanedione added. After stirring for 1 hour, the pH of the mixture is adjusted to 5 to 6 by adding dilute (10 % iger) hydrochloric acid, then the solution is saturated with sodium chloride solution and extracted with ether (4 times 25 ml). The ether extracts are combined, washed with saturated sodium chloride solution (15 ml), dried and concentrated in vacuo to give 6.2 g of crude 3-mercapto-2,5-hexanedione boiling at 57 to "59 ° C at 0.85 torr. NMR, IR and mass spectral analyzes confirm the 3-mercapto-2,5-hexanedione structure.

Example V

(Production of 2-thioacetyl-1,4-butane-dial) (A) Production of 2-butene - 1,4-dial

A mixture of 2,5-dimethoxy-2,5-dihydrofuran (20 g), water (80 ml) and acetic acid (3 drops) for 105 minutes at room temperature, for 22 minutes at 40 ° C and

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Stirred for 90 minutes between 60 and 75 ° C. The GLC analysis indicates 15.7% starting material and 83.5% 2-butene-1,4-dial at this point. The mixture is cooled to 25 ° C and Sodium bicarbonate (0.3 g) is added.

(B) Preparation of 3-thioacetyl-1,4-butanedial

To the aqueous solution obtained in the above (A) is added 10 g of thiolacetic acid over a period of time of 14 minutes added. During the addition, the temperature is kept below 30 ° C by intermittent application of a Cooling bath held. After 110 minutes the reaction mixture is extracted with methylene chloride (3 times 35 ml). The combined Methylene chloride extracts are dried and then concentrated in vacuo to give 17.8 g of a yellow oil, which contains about 80% 2-thioacetyl-1,4-butanedial. The compound is identified by mass spectroscopy, NMR and IR analyzes, the following structure being determined will:

M.S .: No molecular ion; remaining peaks in order decreasing intensity: 43, 29, 27, 45, 55, 60, 84, 100 and 142 m / e units.

NMR: (CDCl ₃ ) £ 2.38 (s, 3) 3.02 (multiplet 2 J = IOHz) 4.46 (t, 1, J = IOHi), 9.40 (s, 1) and 9.68 (s, 1) ppm.

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IR: (thin film) - 2850, 2750, 1720, 17OO (shoulder),

1388, 1352, 1132 and 958 cm ' ¹ .

(C) Production of 3-thioacetylfuran

Into a 500 ml flask equipped with a mechanical stirrer, reflux condenser, addition funnel and thermometer 109 ml of isopropenyl acetate and 0.2 ml of concentrated hydrochloric acid are added. The resulting mixture is heated to reflux and when reflux begins, a solution of crude 2-thioacetyl-1,4-butanedial becomes (prepared in Section B above) in 70 ml of isopropenyl acetate added over a 31 minute period, with is kept under reflux. After the addition is complete, the mixture is refluxed for a further 15 minutes. After cooling down sodium bicarbonate (2.4 g) is added to 25 ° C and the mixture was stirred for 20 minutes. The mixture is concentrated in vacuo and there are 60 ml of benzene and 25 ml Added water. The benzene layer is separated, washed with saturated sodium bicarbonate solution (5 times 25 ml), dried with sodium sulfate and in vacuo to give 14.7 g concentrated in an oil. The vacuum distillation (2.4 mmHg, 50 ° C) yields 1.24 g of a 97.5% pure 3-thioacetylfuran. The structure is determined by mass spectroscopy, NMR and IR analyzes confirmed as 3-thioacetylfuran.

Mass spectrum: molecular ion, then peaks in decreasing order

Intensity: 142, 43, 100, 45, 69, 71, 72 and

73 m / e units.

27 -

509808/1 153

NMR: (CDCl ₃ ) ei 2.34 (s, 3), 6.38 (d, 1 J = 1 Hz) and 7.46 (m, 2 J = 1 Hz) ppm.

IR: (thin film) 3120, 1710, 1495, 1355, 1197, 1147, 1110, 1072, 1010, 953, 940, 870 and 795 cm " ¹ .

Example VI

(Production of 2,5 - dimethyl-3-thioacetylfuran using isopropenyl acetate)

In a 500 ml three-necked round bottom flask fitted with a reflux condenser, If equipped with a thermometer, mechanical stirrer and addition funnel, 225 ml of isopropenyl acetate are added entered. The isopropenyl acetate is then heated to reflux and 0.5 ml of concentrated sulfuric acid is added. A solution of 25 g of 3-thioacetylfuran (prepared according to Example II) in 25 ml of isopropenyl acetate is refluxed for a period of 20 minutes admitted. The mixture is refluxed for an additional 20 minutes and then cooled to room temperature, during this time 10g sodium bicarbonate was added will. After removal of the isopropenyl acetate in vacuo (35 ° at 20 mm) 50 ml of benzene are added and the mixture is placed in a separatory funnel. 10 ml of water are then added to the mixture and when finished The aqueous layer is separated from the evolution of carbon dioxide. The concentration of the organic phase in vacuo (35 ° bath temperature, 20mm) results in 22.2 g of a dark brown

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2437830

Oil. Distillation of the oil gives 16.5 g of 2,5-dimethyl-3-thioa <

boils.

3-thioacetyl-furan, which at 47 to 48 ° C at 0.25 mm

Example VII

(Production of 2,5-dimethyl-3-furanthiol)

In a 1000 ml three-necked flask fitted with a thermometer, reflux condenser, nitrogen inlet, and mechanical stirrer is equipped, 35 g of 2,5-dimethyl-3-thioacetylfuran (prepared by the procedure of Example VI) and 350 ml of 15% sodium hydroxide solution are added. The two-phase mixture is heated to reflux and becomes homogeneous after 35 minutes. The mixture is heated for an additional 20 minutes and cooled to room temperature. The pH of the solution is adjusted to 1 by adding 310 ml of 20% strength sulfuric acid and the resulting mixture is extracted with ether (3 times 100 ml). By washing the combined ethereal solutions with saturated sodium chloride solution (4 times 75 ml) drying with anhydrous sodium sulfate and solvent removal in vacuo (25 ° C at 55 mm) 26.2 g of raw material are obtained. Distillation of the raw material gives 17.3 g of 2,5-dimethyl-3-furanthiol, which boils at 79 ° C at 43 mm. The MS, NMR and IR analyzes confirm that the material is 2,5-dimethyl-3-furanthiol represents.

Example VIII

(Production of 3-thiopropyl-2,5-dimethylfuran)

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In a 500 ml three-necked round bottom flask fitted with a reflux condenser, If equipped with a magnetic stirrer, calcium chloride drying tube and a pot thermometer, 300 ml of isopropenyl acetate are added. The isopropenyl acetate is heated to reflux and 30 g of 3-thiopropyl-2,5-hexanedione are added, At the start of reflux, 0.3 ml of concentrated sulfuric acid is added and the mixture is allowed to stand for 1 Held at reflux for hour and 40 minutes. While cooling, 2 g of sodium bicarbonate are added. After cooling down the solid is separated off by filtration to room temperature and the excess isopropenyl acetate in vacuo deducted. The residue is dissolved in benzene (55 ml) and washed with 10 ml of saturated sodium bicarbonate solution. After drying the solution with sodium sulfate and removing the solvent in vacuo, 36.5 g of a brown one become Obtain oil. 13.4 g of 3-thiopropyl-2,5-dimethylfuran are obtained by vacuum distillation as a light yellow oil which boils at 70 to 71.5 ° C at 4 torr.

NMR, IR and mass spectral analyzes confirm the structure:

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Example IX

(Preparation of 2-methyl-3-furanthiol) (A) 4 -0x0-2-pentanal

In a 5 1 three-necked flask fitted with a mechanical Stirrer, thermometer and vacuum extractor are provided, 600 g of 2-methyl-2,5-dimethoxy-2,5-dihydrofuran and 2400 ml Entered deionized water. After stirring for 20 minutes at room temperature the mixture becomes homogeneous and takes on a pale yellow-green color. Analysis of a sample of the Reaction mixture after 3.25 hours by GLC shows 22% methanol, 67% 4-oxo-2-pentanal and 9% starting material. A vacuum (26 Torr) is applied to the reaction mixture while the temperature of the reaction mixture is between 25 and 30 ° C is maintained. After 3.25 hours GLC analysis shows 13% methanol, 82% 4-oxo-2-pentanal and 3.2% starting material at. The vacuum is removed and the reaction mixture is allowed to stand at room temperature overnight. The analysis after standing overnight shows 12.9% methanol, 85% 4-Q * o-2-pentanal and 2.1% starting material.

(B) 3-thioacetyl-4-oxo-pentanal

In a 5 liter three-necked flask equipped with a mechanical stirrer, thermometer and addition funnel, 2325 ml of the solution obtained in (A) and 2 ml of piperidine, which have been diluted in 5 ml of water, are entered. to

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this solution becomes a mixture of thiolacetic acid (292.3 g) and piperidine (13 ml) added over a period of 20 minutes. After standing for another 10 minutes, will 20 ml of concentrated hydrochloric acid added, the resulting mixture is poured into a separatory funnel and the oil layer is removed. The aqueous layer becomes extracted with benzene (500 ml) and methylene chloride (2 times 500 ml). The benzene extract is combined with the oil layer and the mixture dried over sodium sulfate. The methylene chloride extracts are combined and dried over sodium sulfate. Solvent removal in vacuo (40 to 45 ° C at 15 torr) yields 414.5 g of crude oil from the benzene extract and 17 2.5 g of crude oil from the methylene chloride extracts. The raw one 3-Thioacetyl-4-oxo-pentanal will be given in this form in the next Level used.

(C) 2-methyl-3-thioacetylfuran

In a 12 l three-necked flask equipped with a stirrer, reflux condenser, thermometer and addition funnel, 2950 ml of isopropenyl acetate and 2 ml of concentrated sulfuric acid are entered. The mixture becomes reflux heated and a solution of crude 3-thioacetyl-4-oxo-pentanal (587 g, obtained in section (B) above) in 1170 ml of isopropenyl acetate is used over a period of 35% Minutes added. After refluxing for an additional 40 minutes, sodium bicarbonate (35 g) is added and started removing the excess isopropenyl acetate in vacuo. The pressure will gradually decrease from 200 to 30 Torr decreased while the temperature of the reaction mixture

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falls from 90 to 30 C, at which temperature is maintained until the volume of the reaction mixture is about 1500 ml. The material is further concentrated in vacuo (bath temperature 50 ° C and 5 torr) to give a dark brown oil. The concentrate is diluted with 750 ml of benzene and washed with 250 ml of water. After drying over sodium sulfate, the solvent removal in vacuo (40 to 50 ⁰ C bath temperature and 10 mm) 647 g of a dark brown oil. Distillation of this oil gives 268 g of a material boiling at 67 to 70 ° C. at 1.1 mm, which is 62% 2-methyl-3-thioacetylfuran. Redistillation gives 150 g of 2-methyl-3-thioacetylfuran of 86% purity (determined by GLC), which boils at 73 to 76 ° C. at 5.8 to 6.2 mmHg pressure.

(D) hydrolysis of 2-methyl-3-thioacetylfuran ^ u 2-methyl-3-furanthiol

A 5% solution (1500 ml) of sodium hydroxide in water is heated to reflux under nitrogen. When the reflux begins, 151 g of 2-methyl-3-thioacetylfuran are added over a 15 minute period. After 5 minutes the heating is stopped and the mixture is allowed to cool. When the temperature reaches 30 ° C, 258.1 g Sodium dihydrogen phosphate monohydrate and 10 ml acetic acid were added. After the salt has dissolved, the mixture is extracted with methylene chloride (3 times 250 ml). After drying the methylene chloride extracts by filtration through sodium sulfate and washing the sodium sulfate with 100 ml Methylene chloride, are the combined methylene chloride solutions

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in vacuo (30 ° C at 25 mm) to give 94.8 g of crude Concentrated 2-methyl-3-furanthiols. 64.6 g of 2-methyl-3-furanthiol are obtained by distillation, which at Boils 55 to 56 ° C at 41 to 42 mm.

Example X Production of 2,5-dimethyl-3-thio- (2 "ethylbutyryl) furan

29 g of 2,5-dimethyl-3-furanthiol (0.226 mol) are dissolved in 200 cm ^{3 of} diethyl ether and placed in a 500 ml reaction vessel with 17.8 g of pyridine (0.226 mol). d * -Ethyl-n-butyryl chloride (30.5 g) (0.226 mol) is dissolved in 100 ml of ether and the Cu-ethyl-n-butyryl chloride solution is slowly added to the reaction vessel over a period of 15 minutes. The reaction mass is then stirred for 3 hours and allowed to remain at room temperature for a period of 72 hours.

The reaction mass is then poured into 500 ml of water, creating two phases: an upper layer of ether and a lower aqueous phase. The ether layer is mixed with 500 ml of 4% hydrochloric acid and then with 500 ml washed saturated sodium bicarbonate solution. The ether layer is then dried in anhydrous sodium sulfate and taken under Obtaining an orange-colored oil, crude 2,5-dimethyl-3-thio ~ (2-ethylbutyryl) -furan, concentrated.

The raw material is then at a steam temperature of 87 to 88 ° C and a pressure of 0.55 mmHg to obtain

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16.6 g of a product distilled, which according to IR, NMR and mass spectral analysis has the structure:

Mass spectral analysis;

Molecular ion, then in decreasing intensity: 226 , 43, 71, 128, 99, 41, 39, 127 m / e

NMR spectrum (C. DCl ₀ ): 5.91 (s, 1) 3.62
2.25
2.22
1.64
0.95 (s ^ 3)
(s, 3)
(m, 4)
(t, 6) Example XI

ppm

Production of 2-methyl-3-thio- (2-ethylbutyryl) furan

A solution is placed in a 500 ml reaction flask equipped with a stirrer, thermometer and reflux condenser of 29 g of 2-methyl-3-furanthiol (0.255 mol) dissolved in 195 ml of diethyl ether added. Then 20.2 g Pyridine (0.255 mol) was added to the reaction vessel. 34.5 g ^ -Ethyl-n-butyryl chloride (0.255 mol) are then added in 100 ml

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509808/1153

Diethyl ether is dissolved and this solution is slowly poured into the reaction vessel for a period of 15 minutes entered. When the addition is complete, the reaction mass is stirred for a period of 3 hours and then stirred allowed to stand for 72 hours at room temperature.

The reaction mixture is then poured into 500 ml of water, whereby two phases are obtained: an upper ether layer and a lower aqueous phase. The ether layer is with 500 ml of 4% aqueous hydrochloric acid and then 500 ml of saturated sodium bicarbonate solution. the The ether layer is then dried over anhydrous sodium sulfate and given 43.8 g of a yellow-orange Concentrated oil. This oil is at a temperature of 73.5 to 75 ° C and a pressure of 0.45 to 0.55 mmHg to obtain 39.0 g of 2-methyl-3-thio- (2-ethylbutyryl) furan distilled in the following structure:

Mass spectral analysis:

Molecular ion, then in decreasing intensity: 212 , 43, 41, 39, 71, 99, 114, 113 m / e

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NMR spectrum (CDCl -.); 7.36 (d, 1, J = 1.8Hz)

6.30 (d, 1 _f J = 1.8Hz)

2.48 (m, 1)

2.24 (s, 3)

1.64 (m, 4)

0.96 (t, 6) ppm

Example XII Production of 2, S-dimethyl-S-thio- (2-methylbutyryl) -furan

In a 500 ml reaction flask equipped with a stirrer, thermometer, reflux condenser and addition funnel 29 g of 2,5-dimethyl-3-furanthiol (0.226 mol), dissolved in 200 ml of diethyl ether, were added. 27.4 g of 2-methyl-butyryl chloride (0.226 moles) dissolved in 100 ml of diethyl ether are then added to the addition funnel. During one The 2-methyl-butyryl chloride solution is added over a period of 2 5 minutes in diethyl ether added to the reaction mass from the addition funnel with stirring. When the encore is over, the reaction mass is further stirred for a period of 2 hours. Be at the end of this 2 hour period 17.8 grams of pyridine (0.226 moles) are added to the reaction mass and the reaction mass is over a period of 2 Stirred for hours.

The reaction mass is then poured into 500 ml of water, whereby two phases are obtained: an upper clear orange color Ether layer and a lower aqueous phase in which the pyridine hydrochloride is dissolved.

- 37 -

B09808 / 1 1 53

The ether layer is then mixed with 500 ml of 4% hydrochloric acid and then washed with 500 ml of a saturated sodium bicarbonate solution. The ether layer is then over anhydrous sodium sulfate and concentrated to give 40.8 g of an orange oil which represents crude 2,5-dimethyl-3-thio- (2-methylbutyryl) -furan. This crude material is then distilled at a temperature of 68 to 70.5 ° C and at a pressure of 0.30 mmHg, whereby 33.8 g of a product, 2,5-dimethyl-3-thio- (2-methylbutyryl) -furan, is obtained which has the structure:

Mass spectral analysis:

Molecular ion, then in decreasing intensity: '212 , 128, 57, 43, 85, 41, 39 m / e.

NMR spectrum (CDCl ₃ ):

5.92 (s, 1)

2 _f 66 (q, 1, J = 6Hz)

2.28 (s, 3)

2.23 (s, 3)

1.61 (m, 2)

1.12 (d, 3, J = 6Hz)

0.95 (t, 3, J = 6Hz) ppm

- 38 -

509808/115 3

Example XIII

Production of 2-methyl-3-thio- (2-methylbutyryl) -furan

In a 500 ml flask equipped with a stirrer, thermometer, reflux condenser and addition funnel, 29 g of 2-methyl-3-furanthiol (0.255 mol) are dissolved in 200 ml Diethyl ether added. 30.5 g of 2-methyl-butyryl chloride (0.255 Mol), dissolved in 100 ml of diethyl ether, are then placed in the addition funnel. The 2-methylbutyryl chloride solution is then added to the reaction mass dropwise over a 15 minute period from the addition funnel. 20.2 grams of pyridine (0.255 moles) are then added to the reaction mass and stirring is continued for a further 10 Minutes continued. When the addition is complete, the reaction mass is stirred for a period of 80 minutes, after which it was allowed to stand for 72 hours at room temperature will. The reaction mass is then poured into 500 ml of water to form two phases: an aqueous phase, in which the pyridine hydrochloride is dissolved, and an ether layer, The ether layer is with 500 ml of 4% hydrochloric acid and 500 ml of saturated sodium bicarbonate solution. The ether layer is then dried over anhydrous sodium sulfate and concentrated to give 3 9.1 g of a yellow oil which is crude 2-methyl-3-thio- (2-methylbutyryl) -furan represents. This crude material is then distilled at a temperature of 65 to 66 ° C and a pressure of 0.55 mmHg, whereby 32.7 g of 2-methyl-3-thio- (2-methylbutyryl) -furan of the following structure are obtained:

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2 ^ 37890

Mass spectral analysis:

Molecular ion, then in decreasing intensity: 85, 86, 41, 43, 114, 39 m / e

198.57,

NMR spectrum (CDCl-,) :

7.38 (d, 1, J = 1.8Hz)

6.32 (d, 1, J = 1.8Hz)

2.68 (m, 1)

2.26 (s, 3)

1.67 (m, 2)

1.21 (d, 3)

0.96 (t, 3) ppm

Example XIV Production of 2, S-dimethyl-S-thioisovalerylfuran

In a 25 ml flask fitted with a magnetic stirrer, thermometer and addition funnel, the following are entered:

(i) 2,5-dimethyl-3-furanthiol

(ii) diethyl ether

, g (0.0078 mol)

10 ml

After stirring for 5 minutes, 0.62 g of pyridine (0.0078 mol) is added to the reaction mass. After adding pyridine 0.94 g of isovaleryl chloride (0.0078 mol) dropwise from the addition funnel over 2 minutes to the reaction mass

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2A37890

admitted. A white precipitate forms, which represents pyridine hydrochloride. The temperature in the flask rises to 35 ° C. After stirring for a period of 30 minutes the reaction mass is filtered by vacuum filtration filtered and the filtrate in vacuo to give a yellow-orange liquid (containing a small amount of Contains solid), which weighs 1.56 g, concentrated. The main peak is captured by GLC and measured by mass spectrum, NMR and IR spectra analyzed. It can be confirmed that there is 2,5-dimethyl-3-thioisovalerylfuran of the following structure PRESENTATION:

Mass spectral analysis;

Molecular ion, then in decreasing intensity: 212, 57, 128, 93, 85, 212, 127 m / e.

NMR analysis: (CDC 1st signal

0.97 (d, 6)

interpretation

2.17 (s, 3) 2.22 (s, 3)

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509 808/1 1 53

- 41 - 2U7890

2.45 (m, 2)

5.84 (s, 1) ppm -H

Example XV Production of 2,5-dimethyl-3-thioisobutyrylfuran

In a 25 ml flask equipped with a magnetic stirrer. thermometer and addition funnel, the following are entered:

(i) 2,5-dimethyl-3-furanthiol 1.0 g

(0.0078 moles)

(ii) Diethyl ether (anhydrous) 10 ml

After stirring for 5 minutes, 0.62 g of pyridine (0.0078 mol) is added to the reaction mass. After the pyridine addition, 0.83 g of isobutyryl chloride (0.0078 mole) is added dropwise from the addition funnel to the reaction mass over one minute. A white precipitate forms, which is pyroxyhydrochloride. The temperature in the flask rises to 35 ° C. After stirring for 30 minutes, the reaction mass is filtered by vacuum filtration and the filtrate concentrated in vacuo to give an orange liquid weighing 1.32 g. The material is examined by GLC analysis and the main peak is collected, whereby it can be confirmed by GLC, NMR, IR and the mass spectrum that this 2,5-dimethyl-3-thioisobutyrylfuran has the following structure:

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2A37890

Mass Spectral Analysis:

Molecular ion, then in decreasing intensity 198 , 93, 128, 71, 198, 127 m / e.

NMR analysis (CDCl ₃ ): signal

1.20 (d, 6) interpretation

2.16 (s, 3) 2.22 (s, 3)

H ₃ C

ν 0

CH ₃

2.80 (s, 1) -CH

5.85 (s, 1) ppm -H

509808/1 1 43 -

- 43 - 2A37890

Example XVI Production of 2-methyl · -3-thioisovalerylfur ^ an

In a 2 5 ml flask fitted with a magnetic stirrer, thermometer and addition funnel, the following are entered:

(i) 2-methyl-3-furanthiol 1, O g

(0.0088 moles)

(ii) Diethyl ether (anhydrous) 10 ml

After stirring the mass for 5 minutes, 0.70 g of pyridine is added (0.0088 mol). After the pyridine addition, 1.06 g of isovaleryl chloride (0.0088 mol) is added dropwise from the addition funnel to the reaction mass over 3 minutes. A white precipitate forms which is pyridine hydrochloride. The temperature of the reaction mass rises to 38.degree. After stirring for 30 minutes, the reaction mass is filtered by vacuum filtration and concentrated in vacuo to give a yellow-green liquid containing a small amount of solid and weighing 0.1 g. Using GLC analysis, a sample is analyzed and found to contain 93% product. The main peak is recorded by GLC and by mass spectrum, IR and NMR analysis it can be confirmed that this 2-methyl-3-thioisovalerylfuran has the following structure:

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5 0 9 8 0 8/1153

2 * 37890

Mass spectral analysis:

Molecular ion, then decreasing intensity: 198, 57, 85, 41, 114, 198, 93, 113 m / e

NMR analysis (CDCl ₀ ) :

signal

0.97 (d, 6)

interpretation

CH ₃ tbsp

2.19 (m, 1)

2.21 (s, 3) -CH ₃

2.46 (d, 2) -CH ₂

6.28 (d, 1)

7.31 (d, 1) ppm -H

5098 08/1153 - 45 -

2A37890

Example XVII

Production of 2-methyl-3 - (- 2 ^w thiofuroyl) -furan

In a 25 ml flask fitted with a magnetic stirrer, thermometer and addition funnel, the following are entered:

(i) 2-furoyl chloride 1.14 g

(0.0088 moles)

(ii) Diethyl ether (anhydrous) 10 ml

After stirring for 2 minutes, 0.70 g of dry pyridine (0.0088 mol) is added to the mass. After the pyridine addition 1.0g of 2-methyl-3-furanthiol are dropwise from the Addition funnel was added to the reaction mass over a 2 minute period. The temperature rises to 38.degree and a white precipitate forms (pyridine hydrochloride). The reaction mass is then stirred for 30 minutes and then after this time has elapsed Vacuum filtration filtered. The filtrate is extracted in vacuo to give a yellow liquid weighing 1.65 g concentrated. As can be confirmed by GLC, mass spectrum, IR and NMR spectrum, this material represents 2-methyl-3-thio-furoylfuran the following structure;

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5 0 98 08/1153

2A37890

Mass spectral analysis;

Molecular ion, then decreasing intensity; " 208 , 95, 39, 43, 113 m / e

Nuclear Magnetic Resonance Spectrum (CDCl ₀ ): 7.57 (d, 1)

7.36 <d, 1)

7.30 (d, 1)

6.51 (q, 1)

6.33 (d, 1)

2.26 (s, 3) ppm

Example XVIII

Production of 2,5-dimethyl "-3- (2-thio'furoyl) -furan

In a 25 ml flask fitted with a magnetic stirrer, thermometer and addition funnel, the following are entered:

(i) 2,5-dimethyl-3-furanthiol 1.0 g

(0.0078 moles)

(ii) Diethyl ether (anhydrous) 10 ml

After stirring for 2 minutes, 0.62 g of pyridine (O, OO78 Mol) added to the reaction mass. After the pyridine addition, 1.01 g of 2-furoyl chloride (0.0078 mol) is obtained from the addition funnel added dropwise to the reaction mass over a period of 2 minutes. The temperature of the reaction mass rises to 36 ° C. and a white precipitate forms (pyridine hydrochloride). The reaction mass is then filtered by vacuum filtration and the filtrate in vacuo to an amber liquid which is a

- 47 -

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2A37890

Contains small amount of solid, and weighs 1.26 g, around Contains 87.9% 2,5-dimethyl-3- (2-thiofuroyl) -furan (determined by GLC analysis), concentrated. The mass spectrum and the NMR and IR analysis confirm the structure as:

Mass spectral analysis;

Molecular ion, then in decreasing intensity: 222 , 95, 43, 222, 41, 194, 57 m / e

NMR analysis (CDCl ₀ ) signal

2.23 (s, 3) 2.25 (s, 3)

Iηter pr etat ion

/ ⁰ I.

»C c

CH ₃

5, 92 (see rl). -H 6, 53 (m ,1) -H 7, 19th (see , 1) ppm -H 7, 57 (see -H

509808 Λ1 15.3

- 48 -

2 ^ 37890

Example XIX

Production of 2-Methy1-3- thioctanoylfuran

In a 25 ml flask fitted with a magnetic stirrer, thermometer and addition funnel, the following are entered:

(i) 2-methyl-3-furanthiol 1, Oq

(0.0088 moles)

(ii) Diethyl ether (anhydrous) 10 ml

After stirring the mass for 5 minutes, 0.70 g of pyridine (0.0088 mol) are added. After the pyridine addition, 1.43 grams of octanoyl chloride (0.0088 moles) is added dropwise from the addition funnel to the reaction mass over a 2 minute period. A white precipitate forms (pyridine hydrochloride) and the temperature of the reaction mass rises to 38.degree. When the addition of octanoyl chloride is complete, the reaction mass is stirred for minutes and then filtered by vacuum filtration. The resulting filtrate is then concentrated in vacuo to give an amber liquid containing a small amount of solid and weighing 1.30 g. The main component is collected using GLC and determined by IR, mass spectral and NMR analyzes to be 2-methyl-3-thiooctanoylfuran with the following structure:

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Mass spectral analysis:

Molecular ion, then with decreasing intensity 240 , 57, 177, 43, 114, 41, 240 m / e

NMR analysis (CDCl ₃ ):

Signal interpretation

0.85 (m, 3) -CH ₃

1.38 (m, 8)

1.68 (m, 2) -CH ₂ - 2.2 (s, 3) 2.57 (d, 2) -CH ₂ - 6.25 (d, 1) -H 7.30 (d, 1) ppm -H

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2Ä37890

Example XX

Production of 2,5-dimethyl-3- thiooctanoylfuran

In a 25 ml flask equipped with a magnetic stirrer, thermometer and Addition funnel, the following are entered:

(i) 2,5-dimethyl-3-furanthiol 1.0 g

(0.0078 moles)

(ii) Diethyl ether (anhydrous) 10 ml

After stirring for 3 minutes at room temperature, 0.62 g of dry pyridine (0.078 mol) are added to the reaction mass added. After the pyridine had been added, 1.26 g of n-octanoyl chloride were obtained added to the reaction mass over a 2 minute period from the addition funnel. It forms a white precipitate (pyridine hydrochloride) and the temperature of the reaction mass rises to 35.degree. After this Addition of the n-octanoyl chloride is the reaction mass during Stirred for 30 minutes, after which the mass is filtered by vacuum filtration. The resulting filtrate is in concentrated vacuo to give an amber liquid weighing 1.63 g. The main product is collected using GLC and it can be confirmed by mass spectrum, NMR and IR analysis that it is 2,5-dimethyl-3-thiooctanoylfuran of the following structure:

- 51 -

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2 * 37890

Mass spectral analysis;

Molecular ion, then in decreasing intensity: 254 , 128 57, 43, 254, 127, 41 m / e

NMR analysis (CDCl ₃ ):

Signal interpretation

0.86 (m, 3) - CH ₃ CH ₃

1.28 (m, 8) - / ~ CH ₂ _ / ₄ -CH ₃

64 (m. 2) 0 ρττ —OTT - - Λ 25th (s, 3) · Il ff 0 / 1, 20th (s, 3) -C-CH ₂ CH ₃ 2, HC 2,

2.56 (t, 2) -CH

H ₂

5.84 (s, 1) ppm H.

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2U7890

Example XXI Production of 2,5-dimethyl 1-3-thiobenzoylfuran

In a 50 ml three-necked round bottom flask equipped with a magnetic stirrer, 10 ml addition funnel, nitrogen inlet, Y-tube and thermometer, add 30 ml of diethyl ether, 1.86 g anhydrous pyridine (0.0235 mol) and 3 g 2,5-dimethyl-3-furanthiol (0.023 5 moles). 3.30 g of benzoyl chloride (0.0235 mol) are added over 25 minutes added to the reaction mass with stirring. After the addition of the benzoyl chloride is complete, 6 ml of diethyl ether are added added to the reaction mass, which is then stirred for 40 minutes at room temperature. At the end of this period becomes the resulting slurry (orange solution and heavy white precipitate) filtered through sodium sulfate. The filter cake is washed with diethyl ether. The combined filtrates are concentrated on a rotary evaporator to give a crude yellow oil, which is crude 2,5-dimethyl-3-thiobenzylfuran. Of the The filter cake is then washed with n-pentane (30 ml), whereby a yellow solution is obtained, which is then under Obtaining a heavy yellow oil is evaporated. The oils are combined to give 4.25 grams of raw material, which then at a temperature of 118 to 122 ° C. at 0.5 mm Hg pressure to give 2,5-dimethyl-3-thiobenzoylfuran is distilled, the structure of which was confirmed by mass spectrum, NMR and IR analysis:

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Mass spectral analysis:

Molecular ion, then decreasing intensity: '23 2 , 105, 77, 43, 51

NMR spectrum (CDCl ₀ ): 7.95 (m, 2)

^J ~~~ 7.42 (m, 3)

5.92 (s, 1)

2.26 (s, 3)

2.22 (s, 3) ppm

Example XXII

Production of 2,5-dimethyl-3-thiocinriamoylfuran

5 g of 2 _f 5-dimethyl-3-furanthiol, 40 ml of diethyl ether, 3.08 g of pyridine and 6.48 g of cinnamoyl chloride are placed in a 250 ml flask. The resulting mixture is left to stand for hours. The mixture is then mixed with 17 ml of water, 17 ml of 4% HCl and 17 ml of saturated sodium hydrogen

- '"■ -" carbonate solution washed. The ether layer is then over anhydrous sodium sulfate and dried the solvent in vacuo to give crude 2,5-dimethyl-3-thiocinnamoylfuran, which is a yellow crystalline solid is removed. Recrystallization from hexane gives a sample of

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2,5-dimethyl-3-thiocinnamoylfuran, which is at 64 to 66 ° C
melts and has the following structure:

Mass spectral analysis:

Molecular ion, then in decreasing intensity: 258 , 131,
103 ,. 43, 77 m / e

NMR spectrum (CDCl ₀ ):

7.80 (d, 1, J = 8 Hz)

7.40 (m, 5)

6.70 (d, 1, J = ¹ Hz)

5.90 (s, 1)

2.12 (s, 3)

2.10 (s, 3)

Example XXIII

Production of 2,5-dimethyl-3-thio (m ~ toluoyl) furan

5 g of 2,5-dimethyl-3-furanthiol, 40 ml of diethyl ether, 3.08 g of pyridine and 6.03 g of m-toluoyl chloride entered. The resulting mixture is left to stand for 12 hours. The mixture is then mixed with 17 ml of water, 17 ml of 4% HCl and 17 ml of saturated sodium hydrogen carbonate solution washed. The ether layer is then over anhydrous

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S09808 / 115 3

Dried sodium sulfate and removed the solvent in vacuo to give 2,5-dimethyl-S-thio- (m-toluoyl) furan. The distillation of this residue gives 3.3 g, which boil at 123.5 C at 0.27 mmHg pressure, and have the following structure:

Mass spectral analysis;

Molecular ion, then in decreasing intensity: 246 , 119, 43, 91, 127 m / e

NMR spectrum (CDCl ₃ ):

7 _Λ 76 (m, 2)

7.30 (m, 2)

5.90 (s, 1)

2.43 (s, 3)

2.22 (s, 3)

2.20 (s, 3) ppm

Example XXIV

Manufacture of 2, S-dimethyl-S-furanthiol / sodium hydroxide as a semi-solid mass

In a 50 ml three-necked flask fitted with a reflux condenser,

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2 ^ 37890

If the magnetic tube and thermometer are fitted, 20 ml of methanol and 0.5 g of NaOH are introduced. The mixture is stirred until homogeneous and then 5.1 g of 2,5-dimethy1-3-thioacetylfuran are added. The mixture is left to stand for hours and is then brought to reflux for 2 hours. The resulting orange colored solution is concentrated in vacuo to remove the methanol, resulting in an orange semi-solid material.

Example XXV Production of 2,5-dimethyl-3-thio (2-methylpentenoyl) furan

In a 100 ml three-necked flask equipped with a reflux condenser, calcium chloride drying tube, magnetic stirrer and thermometer, 4.5 g of the semisolid 2,5-dimethyl-3-furanthiol / sodium hydroxide mass prepared by the method of Example XXIV are placed . This material is slurried in 25 ml of tetrahydrofuran, resulting in almost complete dissolution. The resulting solution is then rapidly stirred. To this solution, 4.0 g of 2-methyl-2-pentenoyl rapidly added dropwise over a period of about 1 minute, resulting in a rise in temperature of 2 5 ° C to 37 ⁰ C and the precipitation of a white solid, sodium chloride, leads.

The reaction mass is examined by GLC analysis after 5 and after 30 minutes and both analyzes show that the same material has been produced (GLC conditions: 2.44 m 6.4 mm / ~ 8 'χ 1/4 ^ / SE-30, program from 130 to 225 ° C with 6 ° / min; flow rate-50 ml / min.).

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B09808 / 1153

The reaction mass is then stirred for a period of 1 hour at room temperature. The solids formed in the bulk are removed by gravity filtration and the resulting filtrate is concentrated in vacuo to a reddish-orange liquid weighing 5.2 g. This main material is collected using GLC. The mass spectrum, NMR and IR analyzes indicate that the resulting material is 2,5-dimethyl-3-thiol (2-methylpentenoyl) furan of the structure:

Mass spectral analysis:

Molecular ion, then decreasing intensity; ' 224 , 97, 41, 43, 69, 39, 127

NMR analysis signal

interpretation

1.06 (t, 3rd

CH ₂ -CH ₃

1/92 (s, 3)

CH-

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2.17 (s, 3) 2.22 (s, 3) 2.20 (m, 2)

5.84 (s, 1) H.

6.87 (t, 1) ppm / ^CH 2

Example XXVI

Production of 2-methyl-3-thiopivaloylfuran

In a 25 ml three-necked flask fitted with a reflux condenser, Calcium chloride drying tube, magnetic stirrer, and addition funnel, the following materials are entered:

(i) 2-methyl-3-furanthiol 1.14 g

(0.01 moles)

(ii) Diethyl ether 10 ml

The contents of the flask are stirred for 5 minutes at which time 0.79 g (0.01 mole) of dry, distilled,

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Pyridines are added. After the pyridine addition is complete, 1.20 g (0.01 mol) of pivaloyl chloride are added dropwise from the addition funnel over 1 minute. At this point a precipitate of pyridine hydrochloride is formed. The reaction mass is then stirred for 45 minutes, after which it is brought to reflux (37 ° C) for one hour. At the end of this time, GLC analysis indicates that 80% of the reaction has occurred. The reaction mass consists of a solid and a liquid. The solid is removed by vacuum filtration and the filtrate concentrated in vacuo to a light yellow liquid weighing 1.5 g. The main material is collected using GLC and identified by mass spectrum, MMR and IR spectrum as 2-methyl-3-thio-pivaloylfuran of the following structure:

Mass spectral analysis;

Molecular ion, then in decreasing intensity: 198 , 57, 114, 41, 29, 85, 39

NMR analysis (CDC l ₃ ):

Signal interpretation:

CH, 1.27 ₍ s, 9) _ ^ J

CH ₃

509808/1153 - 6o -

2A37890

2.19 (s _r 3) -CH ₃

6.25 (d, 1) H.

7.30 (d, 1) ppm

Example XXVII

Production of 2,5-dimethyl-3-thiopivaloylfuran

In a 25 ml three-necked reaction flask equipped with a reflux condenser, potassium chloride drying tube, magnetic stirrer and addition funnel the following materials are entered:

(i) 2,5-dimethyl-3-furanthiol 1.28 g

(0.01 mol

(ii) diethyl ether 10 ml

The contents of the flasks are stirred for 4 minutes after which time 0.79 g of pyridine (0.01 mol) is added. After Pyridine addition, 1.20 g (0.01 mol) of pivaloyl chloride is added dropwise from the addition funnel over 1 minute. the

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The reaction mixture is then heated to reflux and am Maintained reflux for 1 hour (37 ° C) after which the reaction mass concentrated to an orange liquid that weighs 2.5 g. The main component is isolated by GLC.

NMR, IR and mass spectrum show that the resulting product is 2,5-dimethyl-3-thiopivaloylfuran of the following structure represents:

Mass spectral analysis:

Molecular ion, then in decreasing intensity: 212 , 57, 128, 43, 112, 41, 127

ISIMR analysis (CDCl ₃ ) signal

interpretation

1.26 (s, 9)

CH ₃

-C-CH, 1 y CH ₃

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2.15 (s, 3) 2.22 (s, 3)

5.84 (s, 1) ppm

Example XXVIII

Production of 2,5-dimethyl-3-thiohexanoylfuran

In a 100 ml three-necked flask equipped with a reflux condenser, Thermometer, magnetic stirrer and calcium chloride drying tube the following materials are entered:

(i) 2,5-dimethyl-3-furanthiol, 3.84 g

(0.03 mol)

(ii) Diethyl ether (anhydrous) 30 ml

The contents of the flask are stirred for 5 minutes, after which 2.37 g (0.03 mol) of pyridine are added. After the pyridine addition 4.02 g (0.03 mol) of hexanoyl chloride are added dropwise over 2 minutes. The reaction mass boils reflux during the addition of the hexanoyl chloride. After the addition is complete, the reaction mass is Stirred at about 38 ° C. for an hour. At the end of this 1 hour period GLC analysis indicates the reaction is complete

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has expired. The solid pyridine hydrochloride product is removed by vacuum filtration and the resulting filtrate is concentrated in vacuo to a reddish-orange liquid weighing 5.0 g. The main material present is isolated using GLC.

Mass spectrum and the IR and NMR analysis show that this material is 2,5-dimethyl-3-thiohexanoylfuran of the following Structure represents:

Mass spectral analysis;

Molecular ion, then in decreasing intensity: 226 , 43, 128, 71, 99, 127, 41, 39, 226.

NMR analysis (CDC l ₃ ):

signal

Thterpr et at ion

0.88 (t, 3)

-CH ₃ CH ₃

1.32 (m, 4)

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2A37890

Il

1.66 (m, 2) -C-CH ₂ -CH ₂ -CH ₂ -

2.16 (s, 3)
2.21 (s, 3)

O 2.56 (t, 2) - C-CH ₂ -CH ₂ -

5.84 (s, 1) ppm H.

Example XXIX

The following preparation was made:

Component parts by weight

liquid hydrolyzed

Vegetable protein 90

4-methyl-beta-hydroxy-ethyl

thiazole 5

Tetrahydrothiophen-3-one 1

Furfuryl mercaptan 0.01

2-nonenal 0> 50 difurfuryldxsulfide, 49

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509 808/115 3

Dimethyl sulfide '. 0.50

Methyl mercaptan 0.50

2,5-dimethyl-3-thiobenzoylfuran 2.00

The 2,5-dimethyl-3-thiobenzoylfuran has a sweetness Mixing effect giving a meat flavor of an undisclosed character towards chicken meat confers. This chemical helps reduce the typical hydrolyzed vegetable protein taste, strengthens the other meat-like chemicals in the preparation and rounds them off.

Example XXX

The following preparation was produced:

Constituent parts by weight

liquid hydrolyzed

Vegetable protein 90

4-methyl-beta-hydroxy-ethyl

thiazole 5

Tetrahydrothiophen-3-one 1

Furfuryl mercaptan 0.01

2-nonenal 0.50

Difurfuryl disulfide, 49

Dimethyl sulfide 0.50

Methyl mercaptan 0.50

2, S-dimethyl-S-thiohexanoyl-

furan 2.00

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The 2,5-dimethyl-3-thiohexanoylfuran gives the preparation specific meat notes. It is sweet and creamy and is reminiscent of white in a very specific way Chicken. In general, it enhances the preparation by giving it a distinct meat character.

Example XXXI

The following preparation was made:

Component parts by weight

liquid hydrolyzed

Vegetable protein 90

4-methyl-beta-hydroxy-ethyl

thiazole 5

Tetrahydrothiophen-3-one 1

Furfuryl mercaptan 0.01

2-nonenal 0.50 difurfuryl disulfide, 49

Dimethyl sulfide 0.50

Methyl mercaptan 0.50

2,5-dimethyl-3-thioacetyl-

furan 2.00

The 2,5-dimethyl-3-thioacetylfuran evokes a distinct roasted meat character in the above preparation and such aroma and taste emerge. It is typically Fleischsossenartxg (roasted meat sauce). The 2,5-dimethyl-3-thioacetylfuran also gives a weak nutty feel

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Note that can be associated with the roasted meat sauce.

Example XXXII

The following preparation was made:

Constituent parts by weight

liquid hydrolyzed vegetable protein 90

4-methyl-beta-hydroxy-ethylthiazole 5

Tetrahydrothiophen-3-one 1

Furfuryl mercaptan 0.01

2-nonenal 0.50 difurfuryl disulfide, 49

Dimethyl sulfide 0.50

Methyl mercaptan 0.50

2-methyl-3-thioacetylfuran 2.00

The 2-methyl-3-thioacetylfuran causes the above preparation has a distinct roasted meat character, while it has a typical sauce-like (roasted meat sauce) Evokes aroma and taste. The 2 ^ methyl-3-thioacetylfuran is stronger and therefore the taste is mostly similar to roasted meat. The sweet and roasted ones Nut notes are very reminiscent of roasted meat sauce.

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Example XXXIII

Preparation a

component

Parts by weight

Ethyl maltoi

Maltol

Vanillin

Methylcyclopentenolone benzaldehyde

Resorcinol dimethyl ether 0.1% (in 95% ethyl alcohol)

absolute Fenuegreek 1% (in 95% ethyl alcohol)

Ethyl oleate

Gamma nonalactone 1% (in 95% ethyl alcohol)

Trimethylpyrazxn 0.1% (in 95% ethyl alcohol)

2-ethyl-5-methylpyrazine 0.1% (in 95% ethyl alcohol) 95% aqueous ethanol propylene glycol

1 2 4 5 1

5 1

5 2

12 60

2, S-dimethyl-S-thio- (2-ethylbutyryl) -furan is added to formulation A the structure

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added in the amount of 0.025%. The resulting mixture is checked by a test group of 4 people with the same mixture (preparation A) but without the 2, S-dimethyl-3-thio- (2-ethylbutyryl) -furan compared to a concentration of 400 ppm in water. It is found that the flavor preparation with the Addition of 2, S-dimethyl-S-thio- (2-ethylbutyryl) -furan has a sweeter character, more toasted hazelnut notes and a longer lasting taste effect than that same preparation but without the 2,5-dimethyl-3-thio (2-ethylbutyryl) -furan.

Example XXXIV

The following preparation was made (butter flavor preparation) :

Ingredient - parts by weight

Diacetyl 60,000 Butyric acid 250,000 Caproic acid 37,000 Caprylic acid 17,000 2,5-dimethyl-3-thioiso-
valerylfuran 0.004 Acetylpropionyl 2,500 Methyl nonyl ketone 0.100 Cyclotene 20,000 delta decalactone 205,000 delta-dodecalactone 408,396

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The 2,5-dimethyl-3-thioisovalerylfuran in the butter flavor above gives 0.004% of the butter a fullness and a sweet creamy effect, when giving flavor Margarine in an amount of 0.04% and approximately the same for baked goods results in the application with 1 to 3 parts / billion

Example XXXV

It was used in "Royal Instant" VaniHepudding (ingredients: Sugar and dextrose, precooked starch, sodium and calcium phosphates, salt, vegetable fat, artificial Flavor and artificial color, vegetable monoglycerides, butylated Hydroxyanisole, butylated hydroxytoluene, citric acid and corn oil; manufactured by Standard Brands, Inc. New York, N.Y.) was made at 80 parts / billion (.008 g of a 0.1% dilution of 2,5-dimethyl-3-thioisovalerylfuran in 100 g pudding) a test group evaluation (5 participants) was carried out. The test group consisting of 5 people agreed agree that the pudding is much sweeter with none * than a pudding without the 2,5-dimethyl-3-thioisovalerylfuran was. The test group consisting of 5 members voted also agreed that the general overall flavor of the pudding "compared to the same pudding but without." Addition of 2,5-dimethyl-3-thioisovalerylfuran was improved.

Example XXXVI

A test group evaluation was carried out in a similar manner zxL

* "depraved character" _ 71 _

509808/1 1 53

those in Example XXXIV with a "Royal Instant" Chocolate pudding made of 2,5-dimethyl-3-thioisovalerylfuran contained in an amount of 80 löilen / billion. The 5 members of the test group agreed that the 2,5-dimethyl-3-thioisovalerylfuran had a significant intermingling. and has a rounding effect on the pudding taste. In addition, 2 of the members of the review group participated indicates that the 2,5-dimethyl-3-thioisovalerylfuran has the character of the cocoa itself, while all 5 members of the test group agreed that the 2,5-dimethyl-3-thioisovalerylfuran the general flavor character of the chocolate pudding compared to the same chocolate pudding, but without 2,5-dimethyl-3-thioisovalerylfu'ran improved.

Example XXXVII

Production of 2-propyl-3-thioacetylfuran

(A) Preparation of 2-propyl-2,5-dimethoxy-2,5-dihydrofuran from 2-propyl furan

reaction

CH ₃ OH

Br,

In a 500 ml three-necked reaction flask fitted with a mechanical Stirrer, calcium chloride drying tube and thermometer

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was equipped, the following materials were brought in:

(i) 2-Propylfuran 25, Og

(0.227 moles)

(ii) absolute methanol 180 ml

(iii) sodium carbonate 47.1 g

(0.454 moles)

The reaction mass is brought to -1OC using a Cooled dry ice acetone bath. Over a period of 20 minutes, a solution of 36.3 g of bromine in 70 ml added dropwise to absolute methanol while maintaining the reaction mass at -12 to -13 ° C. After adding the bromine solution, the reaction mass is stirred for 1.5 hours, this being kept at -10.degree.

The reaction mass is then mixed with 450 ml of saturated sodium chloride solution. The resulting mixture is vacuum filtered and the filter cake washed with 100 ml of methylene chloride. The resulting filtrate and washing solutions are placed in a separatory funnel and the lower organic phase is drawn off therefrom. The aqueous phase is extracted with 200 ml quantities of methylene dichloride and the organic solutions are combined. The organic solution is then dried over anhydrous sodium sulfate and filtered and then concentrated in vacuo to a yellow liquid weighing 32.7 g. The main peak of this material, determined by GLC, contains 2-propyl-2,5-dimethoxy-2,5-dihydrofuran (GLC conditions: F&M 5750; 2.44 mx 6.4 mm; SE-30y 130 225 ° C / min, flow rate -80 ml / min, card advance speed 6.4 mm / min).

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(B) Preparation of 4-oxo-2-heptenal

reaction

Into a 250 ml three-necked reaction flask fitted with a mecha- ' niche stirrer and thermometer, the following materials are entered:

(i) 2-propyl-2,5-dimethoxy-2,5-dihydrofufan, manufactured according to the procedure of part (A)

(ii) (distilled) water

32.7 g (0.16 mol)

325 ml

The reaction mass is stirred for a period of 4 hours at -24 ° C. The reaction mass is at the end of this period in two phases: an aqueous upper phase and an organic lower phase. The aqueous upper phase is decanted and placed in a 1 liter jar for the following Reaction (C) brought.

(C) Reaction of 4-oxo-heptenal with thioacetic acid

reaction

O ^ O

- ^C \ ^{+ H} 3 ^C " ^C \

H SH

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To the stirred aqueous solution of 4-oxo-2-heptenal, generated in part (B) above, 0.4 ml of piperidine is added. After the piperidine has been added 12.4 g of thioacetic acid are added to the reaction mass over a period of 4 minutes, while the reaction mass is at a temperature in the range of 27 to 3 2 ° C is maintained. When the addition of thioacetic acid has ended, the reaction mass becomes stirred for 1.5 hours. The reaction mass is then placed in a separatory funnel and filled with 100 ml of methylene dichloride extracted. The methylene dichloride solution is then separated, dried over anhydrous sodium sulfate and concentrated to an orange oil weighing 23.8 g. This orange oil is obtained using GLC analyzed and found to contain two isomers of the structures given above.

Mass spectral analysis of trap I;

Molecular ion, then in decreasing intensity: 202 , 43, 28, 71, 55, 41, 97, 83 m / e

Mass spectral analysis of trap ΙΊ:

Molecular ion, then in decreasing intensity: 202 , 28, 43, 71, 99 m / e

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(D) Production of 2-propy1-3-thioacetylfuran

reaction

V ^s

In a 500 ml flask equipped with a reflux condenser, calcium chlorine With a drying tube, mechanical stirrer, thermometer, and addition funnel, the following materials were taken brought in:

(i) isopropenyl acetate 175 ml

(ii) concentrated sulfuric acid 0.5 ml

The mass is heated to reflux (93 C) and during a A solution of 23, Og

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of the reaction product of part (C) in 25 ml of isopropenyl acetate was added from the addition funnel to the reaction mass with stirring. The reaction mass is then stirred and held at 91 ^° C. for 30 minutes, at which time 5.0 g of sodium bicarbonate are then added to the mass.

The Isopropenylacetatcyclisierungsmittel is distilled off pressure then at a pot temperature of 80 C and a head temperature of 50 ⁰ C at 60 mmHg. The resulting residue is mixed with 50 ml of benzene and 50 ml of water. The resulting mixture is placed in a separatory funnel and the layers are separated. The benzene layer is filtered through anhydrous sodium sulfate and then concentrated in vacuo to a brown liquid weighing 5.0 g. This liquid is distilled through a Kurzwegmikrodestillationsapparatur at 100 to 103 ⁰ C and 0.3 mm Hg pressure to give 2-propyl-3-thioacetylfuran, as can be confirmed by mass spectrum and NMR analysis.

Mass spectral analysis:

Molecular ion, then in decreasing intensity: 1 84 , 113, 43, 142, 27, 184.

NMR analysis (CDCl ₃ );

Signal interpretation

S 1.01 (t, 3) ^CH 2 ^C S3

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509808/1 1 53

1.65 (m, 2) CH ₂ CH ₂ CH ₃

2.36 (s, 3) 2.59 (t, 2)

6.32 (d, 1) H.

7.35 (d, 1) ppm

H \ O

Example XXXVIII

Production of 2-methyl-3-thioisobutyrylfuran

A mixture of 1.0 g of 2-methyl-3-furanthiol, 0.70 g of pyridine and 10 ml of diethyl ether is placed in a flask and 0.93 g of isobutyryl chloride is added. After standing for 30 minutes, the resulting mixture is filtered and the filtrate concentrated in vacuo to a thoroughly yellow oil which

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24378

Weighs 1.0 g. The product is isolated by preparative GLC. NMR, IR and mass spectral analyzes confirm that the structure of the product 2-methyl-3-thioisobutyrylfuran represents.

Mass spectrum:

Parent ion, then decreasing intensity: 184 , 71, 43, 41, 114, 113 m / e

NMR spectrum (CDCl ₀ ):

7.31 (d, 1), 6.28 (d, 1), 2.83 (m, 1), 2.21 (s, 3) and 1.23 (d, 6) ppm.

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Claims (1)

Claims 1. Process for changing the taste of a food, characterized in that for this purpose at least one connection of the structure __s ^R 2 adds, wherein R, represents a straight-chain or branched alkyl or alkenyl group having 1 to 7 carbon atoms, or R, furyl, thienyl, toluyl, phenylethenyl or phenyl, and wherein each of R ₁ , R ~ and R is hydrogen or lower alkyl . 2. A method for changing the taste of a food, characterized in that one ¹ compound is added to it, which is selected from the group consisting of: 3-thioacetylfuran, 2-methyl-3-thioacetylfuran, 2,5-dimethyl-3-thioacetylfuran, 2-methyl ^ .3-thioisobutyrylfuran, 2,5-dimethyl-3-thioisobutyrylfuran, 2,5-dimethyl-3-thioisovalerylfuran, 2-methyl-3-thioi sovaleryIfuran, 2-methyl-3 (2-thiofuroyl) furan, - 80 - 509808/1153 2,5-dimethyl-3- (2-thiofuroyl) furan, 2-methyl-3-thiooctanoylfuran, 2, S-dimethyl-S-thiooctanoylfuran, 2,5-dimethyl-3-thiobenzoylfuran, 2,5-dimethyl-3-thiopropionylfuran, 2-methyl-3-thiopivaloyIfuran, 2,5-dimethyl-3-thiopivaloyIfuran, 2,5-dimethyl-3-thiohexanoylfuran, 2-propyl-3-thioacetylfuran, 2, S-dimethyl-S-thio- (2-methyl-2-pentenoyl) furan, 2,5-dimethy1-3-thiocinnamoylfuran, 2,5-dimethyl-3-thio (m-toluyl) furan, 2,5-dimethyl-3-thio (2-ethylbutyryl) furan, 2,5-dimethyl-3-thio (2-methylbutyryl) furan, and 2-methyl-3-thio (2-methylbutyryl) furan. 2-methyl-3-thio (2-ethylbutyryl) furan Mass that changes the taste of a food is suitable, characterized in that it is an essential component at least a connection of the structure: wherein R _{fi represents} a straight-chain or branched alkyl or alkenyl group having 1 to 7 carbon atoms, or R _{g represents} furyl, thienyl, toluyl, phenylethenyl or phenyl, and wherein each of R ₁ , R ₂ and R _{4 represent} hydrogen or lower alkyl and a additional flavoring agent. - 81 - 509808/1 153 4. Composition according to claim 3, characterized in that net that the resource selected from the group is, which consists of: Methylthiazole alcohol, 2-methylbutanethiol _f 4-mercapto-2-butanone, 3-mercapto-4-pentanone, 1-mercapto-2-propanone, benzaldehyde, furfural, furfural alcohol, 2-mercaptopropionic acid, 2-pentene, alkylpyrazine, methylpyraz in, 2 -Ethyl-3-methylpyrazine, tetramethylpyrazine, polysulfide, dipropyl disulfide, methylbenzyl disulfide, alkylthiaphene, 2-butylthiaphene, 2,3-dimethylthiaphene, 5-methylfurfural, acetylfuran, 2,4-decadienal , guiacol, pheny! Acetaldehyde, ^ -Decalactone, d-limonene, acetoin, Amyl acetate, maltol, Ethyl butyrate, levulinic acid, Piperonal, ethyl acetate, n-octanal, n-pentanal, hexanal, diacetyl, monosodium glutamate, sulfur-containing amino acids, cysteine, - 82 - 5098 08/1153 hydrolyzed vegetable protein, hydrolyzed fish protein, and Tetramethylpyrazine. Ester of 3-furanethiol of the structure: wherein R 1 is a straight or branched alkyl or alkenyl group having 1 to 7 carbon atoms or Rg is furyl, thienyl, toluyl, phenylethenyl or phenyl, and wherein each of R ₁ , R ₂ and R _{4 is} hydrogen or lower alkyl. 6. Esters according to claim 5, wherein R-, R "and R, are each hydrogen and R _{fi is} methyl, which has the structure and has the name 3-thioacetylfuran. 7. Ester according to claim 5, wherein R- is hydrogen and Rp and R _{1 are} each methyl. 8. The ester of claim 5 having the structure - 83 - 509808/1153 and has the name 2-methyl-3-thioacetylfuran. 9. The ester of claim 5 having the structure and has the name 2,5-dimethyl-3-thioacetylfuran, 10. The ester of claim 5 having the structure and has the name 2-methyl-3-thioisobutyrylfuran. 11, an ester according to claim having the structure and has the name 2,5-dimethyl 1-3-thioisobutyrylfuran. - 84 - 509808/1 1 53 12. The ester of claim 5 having the structure and has the name 2,5-dimethyl-3-thioisovalerylfuran. 13. The ester of claim 5 having the structure and has the name 2-methyl-3-thioisovalerylfuran, 14. The ester of claim 5 having the structure and has the name 2-methyl-3- (2-thiofuroyl) furan, 15. The ester of claim 5 having the structure - 85 - 509808/1153 and the name 2, 5> -dimethyl-3- (2-thiofuroyl) furan having. 16. The ester of claim 5 having the structure and has the name 2-methyl-3-thiooctanoylfuran. 17. The ester of claim 5 having the structure and has the name 2,5-Dimethy1-3-thiooctanoylfuran, 18. The ester of claim 5 having the structure and has the name 2,5-dimethyl-3-thiobenzoylfuran. - 86 - 5098 08/1153 19. The ester of claim 5 having the structure and has the name 2,5-dimethyl-3-thiopropionylfuran. 20. The ester of claim 5 having the structure and has the name 2-Methy1-3-thiopivaloylfuran. 21. The ester of claim 5 having the structure and has the name 2,5-dimethyl-3-thiopivaloylfuran. 22. The ester of claim 5 having the structure - 87 - 509808/1 153 and has the name 2,5-dimethyl-3-hexanoylfuran. 23. The ester of claim 5 having the structure and has the name 2-n-propyl-3-thioacetylfuran. 24. The ester of claim 5 having the structure V \ and the name 2,5-dimethyl-3-thio (2-methyl-2-pentenoyl) has furan. 25. The ester of claim 5 having the structure - 88 - 509808/1 1 53 and the name 2,5-dimethyl-3-thio- (2-ethylbutyryl) has furan. 26. The ester of claim 5 having the structure and the name 2-methyl-3-thio- (2-ethylbutyryl) furan having. 27. The ester of claim 5 having the structure and the name 2,5-dimethyl-3-thic- (2-methylbutyryl) has furan. 28. The ester of claim 5 having the structure - 89 - 509808/1153 89- "24378 and the name 2-methyl-3-thio- (2-methylbutyryl) furan having. 29. Ester according to claim 5, wherein R, phenylethenyl, R _{0 is} methyl, R. is methyl and R _{4 is} hydrogen. 30. Ester according to claim 5, wherein R _{g is} m-toluoyl, R _{2 is} methyl, R _{1 is} methyl and R. is hydrogen. 31. Process for the preparation of substituted and unsubstituted 3-thiafuran compounds, marked by the process stages: (i) Creation of a 2-en-1, 4-dione of the structure: (ii) intimate mixing of the 2-ene-1,4-dione with a thiol having the formula R ₃ SH, creating a substituted or unsubstituted 2-thia-substituted 1,4-dione of the structure: - 90 - 509808/115 3 (iii) Cyclization of the 2-thia substituted 1,4-dione to form a substituted or unsubstituted 3-thiafuran of the formula: wherein R. and R "represent the same or a different lower alkyl group; wherein R3 is acyl, aroyl or alkyl, and R ₄ is hydrogen or lower alkyl. 32. Process for the production of substituted and unsubstituted 3-Th \ afur anverbindungen, characterized through the stages: (i) Creation of a 2-ene-1,4-dione of structure (ii) Intimate mixing in the presence of an organic base of the 2-ene-1,4-dione with a thiol of the formula R ₃ SH, whereby a substituted or unsubstituted 2-thia-substituted 1,4-dione of the structure is created: - 91 - 5098 08/1153 (iii) Cyclization of the 2-thia substituted 1,4-dione to form a substituted or unsubstituted 3-thiafurans of the formula: wherein each of R., R1 and R. is hydrogen or lower alkyl and wherein R is-, acyl, aroyl or alkyl. 33. The method according to claim 32, characterized in that geke- ^ nnzeich net that one as organic base, which in stage (ii) is used, piperidine, pyridine, triethylamine, quinoline or o-picoline is used. 34. Process for making 3-furanethiols of structure - 92 - 509808/1 1 53 characterized by the process stages: (i) creating a 2-ene-1,4-dione of the structure: (ii) Intimate mixing of the 2-ene-1,4-dione with a thiol of the formula R-, SH, whereby a substituted or unsubstituted 2-thia substituted 1,4-dione of the structure created will: (iii) Cyclization of the 2-thia substituted 1,4-dione with formation of a substituted or unsubstituted 3-thiafuran of the formula: - 93 509808/1 1 53 (iv) hydrolysis of 3-acylthia or 3-aroylthia furans, creating a 3-mercaptofuran of the structure is formed: wherein R ₁ and R «represent the same or different lower alkyl groups, wherein R _{3 is} either acyl or aroyl and R _{4 is} hydrogen or lower alkyl. 5. The method according to claim 34, characterized in that the hydrolysis by a Ver ~ driving is carried out, which includes the procedural stages: (i) Mixing dilute alkali metal hydroxide with the acyl or aroyl thiafuran, thereby forming an alkali metal thiafuran - 94 - 509808/1153 where the equivalence ratio of alkali metal hydroxide to acyl or aroyl thiafuran is at least 1: 1; and (ii) mixing the resulting alkali metal thiafuran with dilute acid. 36. The method according to claim 31, characterized in that the cyclizing agent is a Mixture of concentrated sulfuric acid and isopropenyl acetate represents, wherein the ratio of sulfuric acid to isopropenyl acetate is 0.001 up to 0.05. 37. The method according to claim 31, characterized in that the cyclizing agent Isopropenyl acetate used. 38. The method according to claim 32, characterized in that the cyclizing agent a mixture of concentrated sulfuric acid and isopropenyl acetate used, the ratio of sulfuric acid to isopropenyl acetate being 0.001 up to 0.05 amounts to. 39. The method according to claim 32, characterized in that the cyclizing agent is isopropenyl acetate represents. 40. The method according to claim 34, characterized in that the cyclizing agent is a - 95 - 5098 08/1153 24378 Mixture of concentrated sulfuric acid and isopropenyl acetate represents, the ratio of Sulfuric acid to isopropenyl acetate 0.001 up to 0.05 represents. 41. The method according to claim 34, characterized in that the cyclizing agent Isopropenyl acetate used. 42. The method according to claim 31, characterized in that R ₁ and R ~ are each hydrogen. 43. The method of claim 31, wherein R. and R _{2 are} each methyl. 44. The method according to claim 31, characterized in that R _{1 is} hydrogen and R ~ is methyl. 45. The method according to claim 42, characterized in that R ^ represents acetyl. 46. The method according to claim 43, characterized in that R _{3 represents} acetyl. 47. The method according to claim 44, characterized in that R represents acetyl. 48. The method according to claim 31, characterized in that the cyclizing agent 509808/1153 is selected from the group consisting of: (i) a mixture of concentrated sulfuric acid and isopropenyl acetate, the ratio being from sulfuric acid to isopropenyl acetate is 0.001 up to 0.05 and (ii) a mixture of concentrated sulfuric acid and acetic anhydride, the ratio being from sulfuric acid to acetic anhydride is 0.001 up to 0.05. 49. The method according to claim 31, characterized in that the cyclization stage is carried out is in the presence of a mixture of: (i) a first compound that is selected is under sulfuric acid, zinc chloride, boron trifluoride, Boron trifluoride etherates, aluminum trichloride, para-toluenesulfonic acid and boron trichloride; and (ii) a second compound selected from lower acyl anhydrides and enol esters, wherein the weight ratio of the first compound to the second compound is 0.001 up to 0.05. 50. The method according to claim 31, characterized in that the cyclizing agent is a - 97 - 509808/1153 Is a mixture of isopropenyl acetate and sulfuric acid, wherein the molar ratio of isopropenyl acetate to diketone is at least 1: 1 and the weight ratio of sulfuric acid to isopropenyl acetate is 0.001 represents up to 0.05. . Procedure according to. Claim 31, characterized in that the cyclization stage at Temperatures between 25 and 150 C is carried out. 52. The method according to claim 32, characterized in that the cyclization stage at Temperatures between 25 and 150 ° C is carried out. 53. The method according to claim 34, characterized in that the Cyclxsierungsstufe at temperatures between 25 and 150 ⁰ C is performed. 54. The method according to claim 34, marked by the additional method step (v) of the Reaction of the resulting 3-mercaptofuran with a compound known under an acyl halide or an aroyl halide is selected. 50 9 808/1153