Production method capable of improving purity of metformin hydrochloride

Abstract

The invention discloses a production method capable of improving the purity of metformin hydrochloride. N-methyl pyrrolidinone serves as a solvent, dicyandiamide and dimethylamine hydrochloride serve as solutes, the solvent and the solutes are added into a synthesis kettle to react, and stirring, cooling, spin-drying, washing, crystallizing and drying are carried out to obtain metformin hydrochloride. The metformin hydrochloride is prepared through the preparation method provided by the invention, so the yield is 96.4% or higher and the product purity can be 99.93% or higher.

Description

[0001] The present invention is a divisional application of application number 201510197742.2, application date: April 24, 2015, and invention name: "a production method of high-purity metformin hydrochloride". technical field [0002] The invention belongs to the technical field of synthesis of medicinal chemicals, and in particular relates to a production method of metformin hydrochloride with high purity, high yield, low cost and environment friendliness. Background technique [0003] Metformin hydrochloride is a hypoglycemic agent for the treatment of non-insulin-dependent diabetes mellitus. It can improve the blood sugar tolerance of patients with type Ⅱ diabetes and reduce basal and postprandial blood sugar. Its characteristic is that it does not promote the secretion of insulin, but promotes the uptake of glucose by tissues. It has no obvious hypoglycemic effect on normal blood sugar, generally does not cause hypoglycemia, and is relatively safe. In the prevention and...

AI Technical Summary

Problems solved by technology

The synthesis method has a simple process principle and a short production cycle, but still has the following disadvantages: (1) the reaction is incomplete, the raw materials in the early stage of the reaction are solid, and the finished product in the late stage of the reaction is solid, and there is only a short-term homogeneous reaction, and the reaction uniformity is poor. The proportion of raw materials in the reaction is large, which brings difficulties to subsequent refining; (2) The conversion rate of raw materials is low, the product yield is low, and the product benefit is poor; (3) There are potential safety hazards in production

The melting temperature of dicyandiamide and dimethylamine salt exceeds 160°C. When the two materials are higher than the melting point, the reaction speed is fast, which is basically an instantaneous reaction. The temperature rises rapidly in a short period of time, and flushing will occur; The material requirements are harsh, the equipment investment is too large, and the production operation is not easy to control

[0013] The prior art production of metformin hydrochloride has the disadvantages of low purity, low yield, long cycle, high cost, potential safety hazards, and environmental pollution. In the production of metformin hydrochloride, the most critical is dicyandiamide and dimethylamine salt The addition reaction of dicyandiamide, the preparation of raw material dimethylamine hydrochloride, and the drying of finished products have become more and more mature at home and abroad, and their research value is not as good as that of the addition reaction of dicyandiamide and dimethylamine hydrochloride.

Images