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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.
Method used
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Examples
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Embodiment 1
[0049] 1. Add solvent and solute to the synthesis kettle
[0050] The synthesis kettle used is a 1000L glass-lined kettle. The solvent N-methylpyrrolidone 600Kg is sucked into the synthesis kettle by vacuum, the stirring is started, and the solute dicyandiamide 250Kg and dimethylamine hydrochloride 250Kg are added.
[0051] 2. Stir
[0052] (1) Stirring for the first time
[0053] Open the steam valve, turn on the steam to raise the temperature, and use a frequency converter to adjust the stirring speed to 50-60 rpm.
[0054] (2) Second heating
[0055] Stir for 15-20 minutes to raise the temperature of the synthesis kettle to 62°C.
[0056] (3) Adjust the vacuum degree for the first time
[0057] Turn on the vacuum pump, adjust the vacuum degree in the synthesis kettle to 0.04MPa, and continue stirring for 10-20 minutes after the vacuum degree is stable.
[0058] (4) Three heating times
[0059] Open the large steam valve, continue to heat up, and stir for 15-20 minute...
Embodiment 2
[0095] The preparation steps of Example 1 are adopted, and the solvent used is the mother liquor produced in the spin-drying step of Example 1, which is put into a centrifuge from the synthesis kettle and then reused to prepare metformin hydrochloride.
Embodiment 3
[0097] Using the preparation steps of Example 1, the solvent used is the mother liquor produced in the spin-drying step of Example 2, which is put into a centrifuge from the synthesis kettle and continued to be reused to prepare metformin hydrochloride.
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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...
Claims
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Application Information
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