Preparation method of ethyl 5-methyl-2-aminobenzoate

• Main Authors: YAO GUOBIN, CHEN HAIHUA, ZHOU JIANJUN, ZHANG XIANGHUA, ZHENG JINPENG
• Format: Patent
• Language: Chinese; English
• Published: 26.07.2024
• Subjects: ACYCLIC OR CARBOCYCLIC COMPOUNDS; CHEMISTRY; METALLURGY; ORGANIC CHEMISTRY

The invention relates to the technical field of chemical medicines, in particular to a preparation method of ethyl 5-methyl-2-aminobenzoate, which comprises the following steps: refining a 5-methyl-2-nitrobenzoic acid crude product with the content of 80-95%; reducing the 5-methyl-2-nitrobenzoic acid into 5-methyl-2-aminobenzoic acid by using a metal-acid reducing agent; the method comprises the following steps: preparing a 5-methyl-2-aminobenzoic acid ethyl ester crude product solution from 5-methyl-2-aminobenzoic acid under the action of ethanol and an azeotropic entrainer by using an acidic catalyst; concentrating the solution to remove ethanol, layering, and concentrating an organic layer solution again; adding an alcohol solvent and water into the concentrated solution, cooling, crystallizing and filtering; adding an alcohol solvent into a filter cake, pulping, and drying to obtain a finished product of ethyl 5-methyl-2-aminobenzoate. According to the method, the high-purity ethyl 5-methyl-2-aminobenzoat