DE102008002530A1 - Glycidol ester production involves converting alkane carboxylic acid with epichlorohydrin in presence of chrome salt, and received hydroxy compound is converted into alkanoic acid glycidyl esters - Google Patents

Abstract

Glycidol ester production involves converting an alkane carboxylic acid with 1-1.5 mol of epichlorohydrin in presence of 0.0001-0.01 mol of a chrome salt. The received hydroxy compound is converted in presence of an alkali or 1-2 mols of alkaline earth hydroxides into alkanoic acid glycidyl esters. The obtained mixture is extracted, if necessary.

Description

• a) eine Alkancarbonsäure mit Epichlorhydrin in Gegenwart eines Chromsalzes umgesetzt wird
• b) die erhaltene Hydroxyverbindung in Gegenwart eines Alkali- oder Erdalkalihydroxids zum Alkansäureglycidester umgesetzt wird und
• c) das erhaltene Gemisch gegebenenfalls extraktiv aufgearbeitet wird.

The invention relates to a process for the preparation of Alkancarbonsäureglycidestern, which is characterized in that

• a) an alkanecarboxylic acid is reacted with epichlorohydrin in the presence of a chromium salt
• b) reacting the resulting hydroxy compound in the presence of an alkali or alkaline earth metal hydroxide to Alkansäureglycidester and
• c) the resulting mixture is optionally worked up by extraction.

glycidyl because of their physical and chemical properties various uses. you will be z. B. as a reactive diluent for polyacrylates, polyester or epoxy systems are used as dispersing aids, for. B. suitable for pigments or as intermediates in syntheses, especially for the modification of oligomers and polymers used.

It There is therefore a need for simple, inexpensive and the most effective possible synthesis for such glycidyl esters.

Agnieszka Bukowska et al., J. Chem. Technol Biotechnol 74; 1145-1148 (1999) describe the preparation of glycidyl esters by reacting the corresponding carboxylic acids with epichlorohydrin in the presence of chromium (II) salts and subsequent ring closure to the glycidyl ester using acetonitrile and potassium carbonate. The product is purified by distillation.

US 6433217 discloses the preparation of glycidyl esters, especially esters of versatic acid, by reacting the carboxylic acid with epichlorohydrin in the presence of a catalyst, then adding an alkali metal hydroxide and working up by distillation.

Searched are possible alternatives to the previously known production methods. Alternate manufacturing methods should meet the above requirements as far as possible to fulfill the synthesis of glycidyl esters.

Accordingly, became Found the initially defined method.

at the process of the invention is in process step a) a C6 to C12 alkanecarboxylic acid used; in the Alkanecarboxylic acid is an aliphatic compound, which contains a carboxylic acid group and in total from 6 to 12 C atoms, including the C atom of the carboxylic acid group, consists.

The Alkanecarboxylic acid may be linear or branched. It can z. For example, hexanoic acid, octanoic acid, decanoic acid or to branched alkanecarboxylic acids such as neodecanoic acid or versatic acid (branching at the alpha C atom, i. the C atom adjacent to the carboxylic acid group).

Preferably it is a C10 alkanecarboxylic acid.

preferred C10 alkanecarboxylic acids are branched. Comes into consideration z. As the above versatic acid, or neodecanoic acid.

oder 4-Methyl-2-propylhexansäure der Formel

oder ein Gemisch der beiden.Particularly preferred is 2-propylheptanoic acid of the formula

or 4-methyl-2-propylhexanoic acid of the formula

or a mixture of the two.

2-Propylheptanoic acid, 4-methyl-2-propylhexanoic acid, or a mixture of the two as the alkanecarboxylic acid is readily obtained by dimerization of pentenes and subsequent oxidation as described in U.S. Pat DE-A 102 39 134 is described. In the dimerization of the penteno, a mixture of 2-propylheptene and 4-methyl-2-propylhexene is generally formed. The mixture can be worked up and the pure compounds can then be oxidized to the carboxylic acids. In general, however, there is no need for this because both carboxylic acids are suitable for further uses. Preferably, therefore, the mixture is oxidized without separation of the alkenes to the corresponding carboxylic acid mixture. During dimerization and subsequent oxidation, further by-products may be formed, e.g. B. formic acid esters, such as formic acid 1-propyl-hexyl ester or formic acid 3-methyl-1-propyl-pentyl ester, mixtures of nonanol or 6-methyl-octan-4-ol and formic acid, etc. a separation of these by-products before carrying out the invention Procedure is not necessary.

The However, the amount of these by-products is preferably less than 20 Parts by weight, in particular smaller than 10 parts by weight, particularly preferred less than 5 parts by weight per 100 parts by weight of 2-propylheptanoic acid, 4-methyl-2-propylhexanoic acid or its total weight.

2-Propylheptanoic acid can also be obtained by oxidation of the aldehydes, for. B. after WO 2003 018192 or analog US 2 455 241 or according to JACS 1939, 633 (oxidation of the alcohol with KMnO ₄ ), JACS 1997, 12386 (Na ₂ WO ₄ -catalyzed oxidation of the alcohol with H ₂ O ₂ ) or CN 1817845 (with NaOH under pressure and at high temperature, neutralization of the Salt with sulfuric acid).

The mixture particularly preferred according to the invention consists in particular of
1 to 99 wt .-% of 2-propylheptanoic acid and
From 1 to 99% by weight of 4-methyl-2-propylhexanoic acid,
where the percentage is based on the sum of the two.

Particularly preferably, the mixture consists of
10 to 90, especially 20 to 80 wt .-% of 2-propylheptanoic acid and
10 to 90, especially 20 to 80 wt .-% 4-methyl-2-propylhexanoic acid.

in the Process step a) is epichlorohydrin preferably in amounts from 0.9 to 2 mol, more preferably in amounts of from 1 to 1.5 mol, used based on 1 mole of alkanecarboxylic acid.

at the chromium salt may be any salt of chromium (II) or chromium (III) act, in particular are carboxylic acid salts (Alkanoates), e.g. As chromium (II) acetate or chromium (II) ethylhexanoate or Chromium (II) hydroxides or mixed anions (hydroxide and alkanoate).

The Chromium salt is preferably present in amounts of from 0.0001 to 0.01 mole, especially preferably from 0.0005 to 0.005 mol, based on 1 mol of alkanecarboxylic acid used.

The Reaction in process step a) is preferably carried out under atmospheric pressure (1 bar) and at a temperature of 30 to 100 ° C, preferably 60 to 90 ° C performed. In the implementation can a solvent be used; in general but a solvent is not required.

The Implementation in process step a) is preferably carried out by Gas chromatography monitored; Preferably, a complete conversion of the alkanecarboxylic acid to Hydroxy compound.

step b) preferably follows directly process step a) without any refurbishment after completion of the implementation in method step a).

at the alkali or alkaline earth metal hydroxide may be any Hydroxide, preferably an alkali metal hydroxide such as NaOH or KOH act.

The Alkali or alkaline earth metal hydroxide is preferably used in amounts of 1 to 2 mol, based on 1 mol of the obtained in process step a) Hydroxy compound used; the molar amount corresponds to this preferably the amount of the alkanecarboxylic acid used, since in process step a) preferably a complete Implementation takes place.

The Reaction in process step b) is preferably also included Normal pressure (1 bar) and at a temperature of 30 to 100 ° C, preferably 30 to 80 ° C performed.

The Dropping speed is preferably chosen so that the temperature remains in the selected range; after completion the addition of the alkali or alkaline earth metal hydroxide is preferred still some time, z. B. two hours, stirred. A checkpoint the reaction can preferably be carried out by gas chromatography.

Subsequently Preferably, an extractive workup of the after process step b) the mixture obtained. Particularly preferred is an extractive Work-up with water. The obtained aqueous phase and organic phase are separated and the organic phase dried, preferably by adding a desiccant such as sodium sulfate.

Of the Glycidester can in the inventive method be obtained in high purity and yield. With the In addition, the method of the invention is very much simple and inexpensive method for the synthesis of alkanecarboxylic acids to disposal.

Examples

Comparative Example 1

Synthesis of 2-ethylhexanoic acid glycidyl ester analogous to the literature (J. Chem.Technol Biotechnol 74; 1145-1148, 1999)

The Acid (72.0 g, 0.5 mol) was combined with chromium (III) acetate hydroxide (0.10 g, 0.0005 mol) in the flask (250 ml 4-neck flask with condenser, Dropping funnel, magnetic stirrer) submitted, heated and after reaching 80 ° C, the epichlorohydrin (46.3 g, 0.5 mol) was added dropwise over one hour (slight heat of reaction). After stirring overnight at temp., The mixture was added with the addition of acetonitrile (100 ml) with dry Transfer K2CO3 (100 g, 0.72 mol) into a 500 ml flask and stirred at reflux (= 82 ° C) for 2 working days. The cooled mixture was after filtering on a rotary evaporator concentrated and the residue 3 × with ice water shaken. Yield: 65%

Comparative Example 2

Synthesis of 2-ethylhexanoic acid glycidyl ester with Cr (II) -ethylhexanoate as catalyst

The acid (72.0 g, 0.5 mol) was charged together with chromium (II) ethylhexanoate (0.24 g, 0.0005 mol) in the flask (250 ml 4-neck flask with condenser, dropping funnel, magnetic stirrer), heated and after reaching 80 ° C, the epichlorohydrin (46.3 g, 0.5 mol) added dropwise over one hour (slight heat of reaction). After 6 hours of stirring, the mixture was after addition of acetonitrile (100 ml) with dry K2CO3 (69.1 g, 0.5 mol) transferred to a 500 ml flask and at reflux (= 82 ° C) stirred vigorously. The course of the reaction was monitored by GC images. As the conversion of chloride to the epoxide ceased, 20 g of K 2 CO 3 were added and stirring was continued for 2 working days. The reaction effluent was concentrated after separation of the salt residues (Glasfilternutsche) in a rotary evaporator and the residue in a vacuum (1.5 mbar) distilled. Fr.1 Kp = 90 ° C (1.5 mbar) 95.5% by area 2-ethylhexyl glycidyl 1.0 area% isomer 0.95 area% Diolverb. made of epoxy Fr.2 Kp = 90 ° C (1.5 mbar) 96.0% by area 2-ethylhexyl glycidyl 1.0 area% isomer 0.86% Diolverb. made of epoxy Fr.3 Kp = 90 ° C (1.5 mbar) 91.0% by area 2-ethylhexyl glycidyl 1.7 area% isomer 3.0% area Diolverb. made of epoxy swamp 19.5% area 2-ethylhexyl glycidyl 3.5% by area isomer 24.0% area Diolverb. made of epoxy 20 and 22% 2 unknown connections Fr.1 41.1 g Fr.2 20.1 g Fr.3 2.8 g Swamp 21.8 g Total: 95.8 g Theor. Weighing: 100.0 g Yield from fraction 1 + 2: 58.6%

Comparative Example 3

Synthesis of 2-propylheptanoic acid glycidyl ester with distillative workup

The acid (86 g, 0.5 mol) was initially charged together with the chromium (III) acetate hydroxide (0.10 g, 0.0005 mol) in the flask (500 ml 4-necked flask with condenser, intensive stirrer, dropping funnel), heated and after reaching 80 ° C, the epichlorohydrin (46.3, 0.5 mol) added dropwise during one hour (slight heat of reaction). After stirring for 6 h, the mixture was stirred after addition of acetonitrile (100 ml) with dry K 2 CO 3 (100 g, 0.72 mol) at reflux (= 82 ° C). The course of the reaction was monitored by GC images.
Yield after distillation: 61%

Inventive example

Synthesis of 2-propylheptanoic acid glycidyl ester with extractive workup

The acid (688 g, 4 mol) was mixed with the chromium salt (0.8 g, 0.004 mol) in the reactor (3 l jacketed reactor with impeller stirrer and 2 exhaust gas coolers one behind the other.) The jacket of the reactor and the exhaust gas cooling are each heated with and / or cooling thermostats.) heated, after reaching 80 ° C, the epichlorohydrin (398 g, 4.3 mol) added dropwise in 2 hours and stirred for 24 hrs. After GC control, the completely reacted intermediate product was mixed with the sodium hydroxide solution (480 g, 6 mol, 50% strength). The temperature was maintained at 55 ° C. with the aid of the dropwise addition rate. After stirring for 2 hours, the mixture was diluted with 3 l of water, stirred for 10 min at temp., And the two phases were separated after half an hour of settling time. The upper organic phase was dried twice with sodium sulfate. A water determination after filtering off the desiccant showed 0.4% water, after which the product was further dried at 55-115 ° C in a stream of nitrogen. After the stripping process, both epichlorohydrin and other low-boiling components were no longer detectable in the GC. Residual epichlorohydrin was removed by stripping with N ₂ for 3 hours at 115 ° C.
Yield: 66%

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - US 6433217 [0005]
• - DE 10239134 A [0013]
• - WO 2003018192 [0015]
• - US 2455241 [0015]

Cited non-patent literature

• Agnieszka Bukowska et al., J. Chem. Technol Biotechnol 74; 1145-1148 (1999) [0004]

Claims (9)

A process for the preparation of Alkancarbonsäureglycidestern, characterized in that a) an alkanecarboxylic acid is reacted with epichlorohydrin in the presence of a chromium salt b) the resulting hydroxy compound is reacted in the presence of an alkali or alkaline earth metal hydroxide to Alkansäureglycidester and c) the resulting mixture is optionally worked up by extraction. Process according to claim 1, characterized in that in process step a) a C6 to C12 alkanecarboxylic acid is used. A method according to claim 1 or 2, characterized in that in process step a) a C10 alkane carboxylic acid is used. Method according to one of the claims 1 to 3, characterized in that in process step a) 2-propylheptanoic acid, 4-methyl-2-propylhexanoic acid or a mixture of the two is used as alkanecarboxylic acid. Method according to one of the claims 1 to 4, characterized in that epichlorohydrin in amounts of 1 to 1.5 mol, based on 1 mol of alkanecarboxylic acid used becomes. Method according to one of the claims 1 to 5, characterized in that the chromium (II) salt in quantities from 0.0001 to 0.01 mol, based on 1 mol of alkanecarboxylic acid is used. Method according to one of the claims 1 to 6, characterized in that the alkali or alkaline earth metal hydroxide used in amounts of 1 to 2 moles, based on 1 mole of hydroxy compound becomes. Method according to one of the claims 1 to 7, characterized in that in step b) obtained mixture is worked up with water extractively. 2-Propylheptansäureglycidester, 4-methyl-2-propylhexansäureglycidester or their mixtures.