Method for producing metformin hydrochloride from complex solvents

Abstract

The invention discloses a method for producing metformin hydrochloride from complex solvents. The method comprises the steps of dimethylamine hydrochloride preparation and metformin hydrochloride preparation, wherein the metformin hydrochloride preparation comprises the steps of adding raw materials and solvents, heating and warming, cooling, cooling secondarily, centrifuging, washing, crystallizing and drying; the heating and warming comprises the steps of introducing steam into an addition kettle jacket, heating, adjusting a stirring rotation speed to be 80 to 130 turns per minute, warming 30 to 50 minutes to raise kettle temperature to 110 to 115 DEG C, keeping 10 to 30 minutes, continuously warming 15 to 30 minutes to raise temperature to 118 to 125 DEG C and keeping warm to react for 1.5 to 2.5 hours. In the metformin hydrochloride preparation, double components of dimethyl formamide and ethylene glycol monopropyl ether are utilized as the solvents, the metformin hydrochloride can be prepared by using a synergistic effect of two solvents with different characters, product yield is greater than 95%, and purity is greater than 99.90%.

Description

[0001] The present invention is a divisional application of application number 201510197624.1, application date: April 24, 2015, and invention name: "A method for preparing metformin hydrochloride with high purity and high yield from a two-component solvent". technical field [0002] 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 [0003] 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...

AI Technical Summary

Problems solved by technology

[0009] 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

[0012] 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

[0014] (1) The solvent is toxic, producing polluting gas and causing environmental pollution;

[0015] (2) The reaction temperature is high, resulting in high energy consumption and poor safety;

[0016] (3) The reaction time is long, and the production capacity of a single device is poor;

[0017] (4) prone to side reactions;

[0018] (5) Low product purity;

[0019] (6) The reaction yield is low

Images