METHOD FOR PRODUCING AMIDES Russian patent published in 2017 - IPC C07C231/02 

FIELD: chemistry.

SUBSTANCE: invention relates to a method for producing carboxylic acid amide by reaction of an amine of the formula (I), which is selected from methylamine, dimethylamine, ethylamine, diethylamine, n-propylamine, isopropylamine, diisopropylamine, n-butylamine, isobutylamine, t-butylamine, methyl n-propylamine, n-methyl-n-ethylamine and methyl isopropylamine, with a carboxylic acid selected from carboxylic acids having from 3 to 18 carbon atoms which are branched and unsubstituted, from carboxylic acids containing from 3 to 18 carbon atoms, which are preferably straight-chain and unsubstituted and from α-hydroxy carboxylic acids containing from 3 to 12 carbon atoms, which are preferably straight-chain. The molar ratio of the amine according to formula (I) to the carboxylic acid is selected in the range of from 1.5:1 to 1:1. The process includes the following stages (a): reacting the amine according to formula (I) with the mentioned carboxylic acid under the conditions of temperature and pressure at which water and an amine according to formula (I) are gaseous in which reaction (a) is carried out in a single reactor; (b) distilling the formed water together with the unreacted amine according to formula (I), (c) separating the unreacted amine according to formula (I) from water, and (d) reinjecting the mentioned amine according to formula (I) into the reaction mixture at the stage (a). Stages (a) and (b) are carried out without the use of any organic solvent. The reaction at the stage (a) is carried out at a temperature in the range of from 130 to 230°C. In addition, the stage (a) is carried out in a single reactor which is connected to a distillation column and a condenser or in one reactor which is connected to a combination of two distillation columns and two condensers. Reinjection of the amine (I) at the stage (d) is carried out by means of liquid jet nozzles.

EFFECT: production of amides of carboxylic acids with high yield and satisfactory purity, which does not require a large excess of amine.

6 cl, 3 ex