A method for preparing metformin hydrochloride with high purity and high yield by two-component solvent

Abstract

The invention discloses a method for preparation of high purity and high yield metformin hydrochloride by a two-component solvent. The method includes: preparation of dimethylamine hydrochloride and preparation of metformin hydrochloride. During preparation of dimethylamine hydrochloride, dimethylamine gas and 31% hydrochloric acid are adopted as the raw materials to carry out reaction, through co-cooling of a cooler and a reaction kettle jacket, pumping circulating, spraying absorption of dimethylamine tail gas and absorption of dimethylamine tail gas by hydrochloric acid, the utilization rate of the raw materials is maximumly ensured, the loss of raw materials is reduced, and the product yield is improved. During preparation of metformin hydrochloride, dimethylformamide and ethylene glycol monopropyl ether two components are used as the solvent, the synergistic effect of the two solvents with different natures are utilized, and the prepared metformin hydrochloride product has yield of over 95% and purity of more than 99.90%.

Description

technical field [0001] The invention belongs to the technical field of organic synthesis, and in particular relates to a production method for preparing metformin hydrochloride with high purity and high yield by using a two-component solvent. Background technique [0002] Metformin hydrochloride, like other guanidine substances, has strong physiological activity, can reduce fasting and postprandial hyperglycemia in patients with type Ⅱ diabetes, and can reduce glycosylated hemoglobin (HbAlc) by 1% to 2%. It has a unique treatment for type 2 diabetes It can significantly improve the patient's glucose tolerance and hyperinsulinemia, reduce plasma free fatty acid and triglyceride levels, has few side effects, and has high safety. It is currently the most commonly used hypoglycemic drug in clinical practice. The drug has multiple mechanisms of action, including delaying glucose uptake from the gastrointestinal tract, increasing peripheral glucose utilization by improving insulin...

AI Technical Summary

Problems solved by technology

[0008] Disadvantages: (1) The organic solvents currently used in the process include cyclohexanol, tert-amyl alcohol, benzene, etc., and their toxicity and difficulty in recycling make them harmful to the environment; (2) The reaction temperature is high, generally 130-160°C, high energy consumption; (3) The reaction time is long, and multiple side reactions are prone to occur; (4) The number and content of impurities in the crude metformin hydrochloride obtained are large, and a large amount of ethanol or methanol is required for refining Higher product cost due to low boiling point solvents

[0011] Disadvantages: (1) Stirring resistance is large, because there is no solvent, the reactant becomes viscous in the molten state, the fluidity is not good, and the resistance to stirring is large; (2) The reaction temperature is difficult to control. In the melting reaction, because there is no After adding the solvent, the reactant is heated to melt, the heat is lost slowly, and it is difficult to control the reaction temperature

[0013] (1) The solvent is toxic, produces polluting gas, and causes environmental pollution;

[0014] (2) The reaction temperature is high, resulting in high energy consumption and poor safety;

[0015] (3) The reaction time is long, and the production capacity of a single device is poor;

[0016] (4) prone to side reactions;

[0017] (5) Low product purity;

[0018] (6) Low reaction yield

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