High-purity metformin hydrochloride preparation method

Abstract

The invention discloses a high-purity metformin hydrochloride preparation method. N-methyl pyrrolidone is used as a solvent, dicyandiamide and dimethylamine hydrochloride are taken as a solute, the solvent and the solute are added into a synthesis kettle for reaction, and metformin hydrochloride is prepared through steps of stirring, cooling, spin-drying, washing, crystallizing and drying. The metformin hydrochloride prepared through the preparation method provided by the invention has the advantages that the yield is higher than 96.4 percent, and the product purity is higher than 99.93 percent.

Description

technical field [0001] 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 [0002] 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 treatment of diabetes, metformin hydrochloride is used more and more widely and has become an irreplaceable oral hypoglycemic drug. Insulin resistance (IR) is one of the independent risk factors for cardiovascu...

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

[0012] The existing technology produces metformin hydrochloride with low purity, low yield, long cycle, high cost, potential safety hazards, environmental pollution and other deficiencies in the production of metformin hydrochloride. In production, the most critical thing is the addition reaction of dicyandiamide and dimethylamine hydrochloride. The domestic and foreign research and application of dimethylamine hydrochloride preparation and finished product drying have become increasingly mature, and its research value is not as good as that of dicyandiamide. Addition reaction with dimethylamine hydrochloride

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