FIELD: chemistry.
SUBSTANCE: invention relates to a method of producing 3-(2-chloropropionyl)amino-4-methyl-2-methoxycarbonylthiophene by acylation of 3-amino-4-methyl-2-methoxycarbonylthiophene with 2-chloropropionyl chloride through simultaneous addition to a reaction mixture containing 3-amino-4-methyl-2-methoxycarbonylthiophene, 2-chloropropionyl chloride and an alkaline component with relative speed which enables to maintain pH of the medium in aqueous phase in the range of 4.0-8.0.
EFFECT: preventing or minimising secondary reactions of alkaline hydrolysis of 2-chloropropionyl chloride during acylation of 3-(2-chloropropionyl)amino-4-methyl-2-methoxycarbonylthiophene and achieving high output and quality of the product, which is used in synthesis of biologically active compounds and is particularly a key intermediate product in synthesis of hydrochloride of methyl ether of 4-methyl-3-[2-(n-propylamin)propionylamino]thiophene-2-carboxylic acid - one of the best local anaesthetics, known as articaine or ultracaine.
1 cl, 1 ex
