Process for synthesizing ethenylamidine hydrochloride by one-step method

Abstract

The process of synthesizing ethyl amidine hydrochloride includes: setting acidyl methoxide into synthesizing kettle, dropping acetonitrile, maintaining at 15-30 deg.c for 4-6 hr before lowering the temperature to -5 deg.c to 20 deg.c, adding amido alcohol, stirring to react, cooling after reaction and discharging, solid-liquid separation, concentrating and centrifugally separating to obtain ethyl amidine hydrochloride. The synthesizing kettle is provided with a valve in the discharge port for measuring temperature, and the concentrating kettle is provided with a stirrer for favoring heat transfer and mass transfer. The present invention has optimized aminating condition, less reaction step, simplified reaction apparatus, high yield and high product quality.

Description

technical field [0001] The invention belongs to the manufacturing method of fine chemical products-medicine intermediates, in particular to the synthesis process of acetamidine hydrochloride. Background technique [0002] Acetamidine hydrochloride is made from acetonitrile, hydrogen chloride, methanol and ammonia through addition ammoniation, and its reaction formula is as follows: [0003] [0004] [0005] HCL+NH 3 →NH 4 CL [0006] The process is: [0007] ① Preparation of raw materials: dry HCL is absorbed with methanol to make 45%-48% acid methanol for later use. Dried ammonia is absorbed with methanol to make 12%-14% ammonia methanol for later use. [0008] ②Synthesis: Put 45-48% acid methanol into the imidine synthesis kettle at one time, start stirring, cool down, add acetonitrile dropwise into the imidine synthesis kettle at 8-15°C, and finish adding dropwise in about 4-6 hours . Keep warm at 18-24°C for 4-6 hours, depending on the reaction state of the...

AI Technical Summary

Problems solved by technology

If in a large reaction kettle, the material is only at the bottom of the kettle, the thermometer cannot be inserted into the material at all, and the temperature of the material cannot be truly measured, which will bring great difficulties to the operation.

During the ammoniation, the volume of the material increases three times, and the small kettle cannot hold it. In order to solve this problem, the existing technology adopts the synthesis of imidine in the small kettle, and the ammoniation in the large kettle is used to synthesize the acetamidine hydrochloride, so that the synthesis of the acetamidine hydrochloride is divided into two steps. Multi-purpose equipment and multi-purpose personnel also limit the production capacity of acetamidine hydrochloride

[0011] The concentration kettle in the prior art has an unreasonable design and cannot meet the requirements for the concentration of acetamidine hydrochloride. Without stirring, it is not conducive to the mass and heat transfer. It is difficult for the material in the center of the kettle to obtain the required heat, because The distance of heat and mass transfer is relatively long

In order to obtain the required heat, it is necessary to increase the external heat supply, especially in the later stage of concentration, when the material thickens and appears solid, heat transfer is more difficult. The result of increasing the external heat supply will inevitably cause local overheating of the material. Partially decompose the material, polymerize and form hard lumps, which seriously reduces the product quality (appearance and internal), and also reduces the yield of the product

[0012] There are two methods of ammoniation in the prior art: low-temperature ammoniation and hig

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