Preparation method of N-p-aminobenzoyl-L-glutamic acid

Abstract

The invention discloses a preparation method of N-p-aminobenzoyl-L-glutamic acid. The preparation method comprises the following steps of: (1) adopting p-nitrobenzoic acid as a starting material, adopting oxalyl chloride as an acylating chlorination reagent, adopting tetrahydrofuran and DMF (Dimethyl Formamide) as a mixed solvent, and carrying out acylating chlorination reaction to prepare paranitrobenzoyl chloride; (2) carrying out condensation reaction of the paranitrobenzoyl chloride prepared in the step (1) and sodium glutamate to prepare N-p-nitrobenzoyl-L-glutamic acid; (3) adopting hydrazine hydrate as a reducing agent, adopting ferric trichloride hexahydrate as a catalyst, and carrying out reducing reaction of the N-p-nitrobenzoyl-L-glutamic acid prepared in the step (2) to preparethe N-p-aminobenzoyl-L-glutamic acid. The preparation method disclosed by the invention has the beneficial effects that the acylating chlorination reaction selects the oxalyl chloride as the acylating chlorination reagent in the mixed solvent of the tetrahydrofuran and the DMF, the reducing reaction selects the hydrazine hydrate as the reducing agent and selects the ferric trichloride hexahydrateas the catalyst, and finally the N-p-aminobenzoyl-L-glutamic acid with the purity being more than or equal to 99.9% can be obtained.

Description

technical field [0001] The invention belongs to the technical field of fine chemicals, and in particular relates to a preparation method of N-p-aminobenzoyl-L-glutamic acid. Background technique [0002] N-p-aminobenzoyl-L-glutamic acid is an intermediate in the synthesis of anti-anemia drug folic acid, and its structure is as follows: [0003] . [0004] Chinese patent literature CN105439895A discloses a preparation method of N-p-aminobenzoyl-L-glutamic acid, which uses p-nitrobenzoic acid as a starting material, and first prepares p-nitrobenzoyl chloride through acid chloride reaction , and then make N-p-nitrobenzoyl-L-glutamic acid through condensation reaction with sodium glutamate, and finally get N-p-aminobenzoyl-L-glutamic acid through reduction reaction. The deficiency of this method is: the purity of N-p-aminobenzoyl-L-glutamic acid is less than 99.9%. Contents of the invention [0005] The purpose of the present invention is to solve the above problems, and ...

AI Technical Summary

Problems solved by technology

The disadvantage of this method is that the purity of N-p-aminobenzoyl-L-glutamic acid is less than 99.9%.