DE1186044B - Process for the preparation of N-sulfonyl-N-alkyl-urethanes - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Boarding school Class: C 07 c

German KL: 12 ο -17/01

Number: 1186 044

File number: F40739IVb / 12o

Filing date: September 12, 1963

Opening day: January 28, 1965

N-alkylated urethanes or N-alkylated N-sulfonyl urethanes can be achieved by reacting the corresponding isocyanates with alcohols and then Obtained alkylation of the urethanes or sulfonyl urethanes obtained with an alkylating agent. the Possibility of producing the desired compounds in one operation - for example by adding alcohol to the C = N double bond of the isocyanates and simultaneous introduction of the N positions Alkyl group -, did not exist before.

It is known that alkyl and aryl isocyanates react with orthoesters at elevated temperatures and under the catalytic influence of Lewis acids. In the process, 1: 1 adducts are formed which, however, ^{disintegrate again into the starting components at 100 to 150 °} C. (Angew. Chemie, 74, p. 872 [1962]). This tendency towards thermolytic cleavage is a phenomenon that can generally be observed in isocyanate adducts (Houben-Weyl, Stuttgart, 1952, vol. 8, p. 130).

It has now been found that N-sulfonyl-N-alkyl-urethanes the general formula

x -so.-N;

COOR

wherein R is an alkyl radical and X is a halogen atom, an aryl, substituted aryl group or the radical -NR-COOR means obtained when using orthocarboxylic acid ester the general formula

R '

/ OR

C OR

OR

Process for the production of
N-sulfonyl-N-alkyl urethanes

wherein R has the abovementioned meaning and R 'is a hydrogen atom, an alkyl or aryl group represents, with sulfonyl isocyanates of the formula

O = C = N - SO ₂ - X '

in which X 'denotes a halogen atom, an aryl, substituted aryl or an isocyanate group, at -80 to + 120 ^° C., optionally in inert diluents.

Surprisingly and in contrast to the known addition reaction of the orthocarboxylic acid esters on isocyanates that do not contain a sulfonyl group in the molecule, the process according to the method proceeds Implementation exothermic, without a catalyst and is irreversible. In the course of the reaction, the Orthocarboxylic acid ester the corresponding normal applicant:

Farbwerke Hoechst Aktiengesellschaft

formerly Master Lucius & Brüning, Frankfurt / M.

Named as inventor:

Dr. Hans Biener, Kelkheim (Taunus)

Carboxylic acid ester. As a result, one can see the emergence of N-sulfonyl-N-alkyurethane as an addition the alkyl and alkoxy group derived from the orthocarboxylic acid ester on the sulfonyl isocyanate. Thus, the process found allows an addition of Make dialkyl ethers to sulfonyl isocyanates and, in contrast to the prior art, offers the Possibility of synthesizing N-alkylated N-sulfonyl urethanes in one procedural stage.

Because of the better accessibility of the starting material and the smoother course of the reaction shorter alkyl radicals are preferably orthoesters of formic acid with lower alcohols, such as Methanol, ethanol, propanol, butanol and isopropanol or isobutanol are used, but can carry out the reaction with orthoesters of medium alcohols such as octyl alcohol. Furthermore, one can Use orthocarboxylic acid esters in which R 'is an aliphatic or aromatic radical, for example is a methyl or phenyl group.

Halogen sulfonyl isocyanates are used as sulfonyl isocyanates, such as fluoro- or chlorosulfonyl isocyanate, into consideration. Furthermore, sulfonyl diisocyanate and arylsulfonyl isocyanates in which the aryl radical is, for example, a substituted or unsubstituted one Phenyl or naphthyl group can be used for the reaction. As suitable substituents Halogen atoms, alkyl or alkoxy groups come into consideration.

According to the method the reaction can be in the temperature range from -80 to +120 ⁰ C perform. Preferably carried out between -20 and +50 ⁰ C, where room temperature is generally sufficient for its completion.

Especially with the very violently reacting halogen sulfonyl isocyanates is in the implementation of the

409 770/391

Implementation of the use of inert, low-boiling diluents is expedient. As such come chlorinated hydrocarbons, for example methylene chloride, chloroform, carbon tetrachloride, as well as dialkyl ethers, benzene or petroleum ether into consideration. The work-up of the N-sulfonyl-N-alkyl urethanes produced takes place, if appropriate after evaporation of the solvent used, more expediently Way by fractional distillation in a high vacuum.

Some of the compounds obtained according to the process have not yet been described and are based Their reactive groups are valuable intermediates for a wide variety of syntheses, for example of pesticides, dyes or textile auxiliaries.

example 1

A mixture of 53 g of trimethyl orthoformate and 50 ml of methylene chloride is cooled to -20 ⁰ C and slowly added with stirring 43.5 ml of chlorosulfonyl isocyanate, wherein the reaction temperature is maintained at -10 ~ 0 ^c C by external cooling. The mixture is left to stand for a further hour at room temperature, the methylene chloride and the methyl formate formed in the course of the reaction are evaporated off under reduced pressure and finally the colorless residue is distilled. The N-methyl-N-chlorosulfonyl-methyl urethane is almost completely transferred at 44 to 46 ° C / 0.3 Torr. The yield is 92% of theory, the refractive index rig = 1.4607.

Example 2

35

A mixture of 17.4 ml of chlorosulfonyl isocyanate and 20 ml of chloroform is added to 47 g of tri-n-butyl orthoformate in 80 ml of chloroform at 20 to 25 ° C. with stirring. When the addition is complete, the chloroform is distilled off using a water jet pump and the residue is fractionated over a 40 cm long Vigreux column. Boiling point of Nn-butyl-N-chlorosulfonyl-n-butyl urethane: 87 to 90 ° C / 0.2 Torr, rig = 1.4488; the yield is 77% of theory.

Example 3

One at - 10 ⁰ C prepared mixture of 45 g triethyl orthoformate and 55 g of phenylsulfonyl isocyanate is allowed to stand as long as at room temperature, no longer responds to a sample with water, which takes about 12 hours to complete. The viscous, colorless reaction product is then fractionated over a 40 cm long Vigreux column at 0.2 torr. The first run consists essentially of residues of unreacted starting components and can be reused after cleaning. The N-ethyl-N-phenylsulfonyl-ethyl urethane boils at 117 to 12PC / 0.15 Torr. The yield corresponds to 53% of theory. Refractive index «!? - 1.5150.

Example 4

120 g of triethyl orthoformate in 50 ml of methylene chloride are added at 15 ⁰ C with stirring and external cooling with 60 g Sulfonyldiisocyanat. After 1 hour, the solvent and the ethyl formate formed by the reaction are distilled off at 20 torr. The remaining colorless oil solidifies when left standing in the refrigerator for a long time. Recrystallized from ethanol, large prisms with a melting point of 54 ° C. are obtained. If not entirely pure starting materials are used, crystallization cannot be achieved; in this case the N ^ '- sulfonyl-bis-CN-ethyl-ethyl urethane) is purified by distillation. Boiling point: 96 to 100 ° C / 0.2 Torr. The yield is 36% of theory.

Example 5

232 g of tri-n-butyl orthoformate and 200 g p-Toluylsulfonyl-isocyanat are with cooling mixed and left to stand for 12 hours at room temperature. After distillation over a 40 cm long Vigreux column, 185 g of N-n-butyl-N-tosyl-n-butyl urethane are obtained from boiling point 155 to 160 ° C / 0.3 Torr and refractive index «!," = 1.5038. The yield corresponds to 61% of theory.

Example 6

With cooling and stirring a mixture of 14 g is orthobenzoic acid trimethyl ester and 20 ml of methylene chloride with 14.5 g phenylsulfonyl isocyanate added, the temperature should not exceed 30 ⁰ C. The batch is stirred for a further 1 hour, the solvent is evaporated off using a water jet pump and fractionated over a 40 cm long Vigreux column. The N-methyl-N-phenylsulfonyl-methyl urethane goes over at 127 to 128 ° C / 0.25 Torr. The refractive index is n'g = 1.5300. Yield about 10% of theory.

Example 7

They place 54 g orthoacetic acid triethyl before and leaves at 0 ⁰ C under stirring 29 ml of chlorosulfonyl isocyanate are added dropwise. After standing for 2 hours at room temperature, the brown reaction product is fractionated over a 40 cm long Vigreux column. 20.5 g of N-ethyl-N-chlorosulfonyl-ethyl urethane are obtained, corresponding to a yield of 28% of theory, with a boiling point of 65 to 67 ° C./0.2 Torr and a refractive index nl ° = 1.4929.

Claims (1)

Claim: Process for the preparation of N-sulfonyl-N-alkyl-urethanes the general formula X-SO ₂ -N COOR wherein R is an alkyl radical and X is a halogen atom, an aryl, substituted aryl group or the radical - NR - COOR means, characterized in that one orthocarboxylic acid ester the general formula R '--C OR
OR
OR where R has the above meaning and R ' 5 6 a hydrogen atom, an alkyl or aryl group, optionally in inert diluents, represents, reacts with sulfonyl isocyanates of the formula. O = C = N - SO ₂ - X ', where X' is a halogen atom, an aryl, substituted aryl, or iso- Considered publications: cyanate means at -80 ° to +120 ⁰ C, 5 Angewandte Chemie, Vol. 74, p 872 (1962). 409 770/391 1.65 © Bundesdruckerei Berlin