Preparation method of acetamidine hydrochloride

A technology for acetamidine hydrochloride and acetamidine hydrochloride is applied in the field of preparation of acetamidine hydrochloride, and can solve the problems of unsafe ammoniation reaction, high consumption of acetonitrile and liquid ammonia, easy decomposition of reaction products and the like

Pending Publication Date: 2021-08-31
内蒙古益泽制药有限公司 +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0005] Patent CN101134737B discloses a one-step process for synthesizing acetamidine hydrochloride, although it can effectively improve the efficiency of equipment use and increase production, but because the ammoniation reaction is carried out under acidic conditions, the ammoniation reaction is unsafe and the reaction product is easy to decompose , high consumption of acetonitrile and liquid ammonia

Method used

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  • Preparation method of acetamidine hydrochloride
  • Preparation method of acetamidine hydrochloride
  • Preparation method of acetamidine hydrochloride

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preparation example Construction

[0036] Preparation of ethyleneamidine

[0037] The present invention has no special requirements on the preparation of ethyleneamidine, and methods commonly used in the art can be used.

[0038] Preferably, it is prepared by the following method:

[0039]

[0040] (i-1) Add acetonitrile dropwise to methanol hydrochloride, the initial dropping temperature is 0-5°C, the dropwise addition is completed within 10-15°C, and react at 10-15°C for 10-16 hours to obtain Acetamidine.

[0041] In another preferred example, in step (i-1), the mass percentage of HCl in methanol hydrochloride is 45-50%.

[0042] Preferably, the molar ratio of acetonitrile:HCl:methanol is 1:1.02-1.12:1.25-1.5.

[0043] Usually, the methanol hydrochloride is prepared by passing dry hydrogen chloride into methanol.

[0044] In the present invention, more preferably, the reaction solution obtained in step (i-1) is directly used in the synthesis of acetamidine hydrochloride.

[0045] Preparation of acetam...

Embodiment 1

[0063] A preparation method of acetamidine hydrochloride, comprising the following steps:

[0064] (1) Synthesis of ethyleneamidine

[0065] Add 3.10 mol of methanol to a 500ml four-necked flask equipped with a stirrer and a thermometer, pass through 2.5 mol of dry HCl to make methanol hydrochloride, add 2.3 mol of acetonitrile to the methanol hydrochloride dropwise, and the initial dropping temperature is 5°C , The dropwise addition is completed within 10°C, and the temperature is kept at 10-15°C for 10 hours to synthesize ethyleneamidine.

[0066] (2) Synthesis of Acetamidine Hydrochloride

[0067] Add 4.5 mol of methanol dropwise to ethyleneamidine (reaction solution directly obtained in step (1)) to dilute, and add ethyleneamidine dropwise to 260.0 g mass concentration in 17% ammonia methanol (excessive amount of ammonia methanol), the initial drop The adding temperature is 0-5° C., the dropwise addition is completed within 15° C., and the temperature is kept at 25-28° C...

Embodiment 2

[0069] A preparation method of acetamidine hydrochloride, comprising the following steps:

[0070] (1) Synthesis of ethyleneamidine

[0071] Add 2.5mol of methanol to a 500ml four-necked flask equipped with a stirrer and a thermometer, and pass through 2.16mol of dry HCl to make methanol hydrochloride. Add 2.0mol of acetonitrile to the methanol hydrochloride dropwise, and the initial dropwise temperature is 7°C , The dropwise addition is completed within 10°C, and the temperature is kept at 10-15°C for 16 hours to synthesize ethyleneamidine.

[0072] (2) Synthesis of Acetamidine Hydrochloride

[0073] Add 4.0 mol of methanol dropwise to ethyleneamidine (reaction solution obtained directly in step (1)) to dilute, and add ethyleneamidine dropwise to 213.7 g of ammonia methanol with a mass concentration of 18.9%, and the initial dropwise temperature is 3 ℃, the dropwise addition is completed within 15 ℃, and the temperature is kept at 25-30 ℃ for 3.0 hours, and the pH=8-9 is de...

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Abstract

The invention provides a preparation method of acetamidine hydrochloride. Specifically, an intermediate product acetamidine is dropwise added into aminomethanol to generate stable acetamidine hydrochloride by adopting a reverse dropwise adding mode, wherein the decomposition of acetamidine is effectively inhibited by adopting the reverse dropwise adding mode, and the yield of acetamidine hydrochloride can reach 95% or above. The method is safe to operate, high in yield, low in energy consumption and very suitable for large-scale application.

Description

technical field [0001] The invention relates to the field of chemical synthesis, in particular to a method for preparing acetamidine hydrochloride. Background technique [0002] Acetamidine hydrochloride, also known as α-amino-α-iminoethane hydrochloride, is a white or yellowish long prismatic crystal, easy to deliquescence, has a peculiar smell, soluble in water and ethanol, insoluble in acetone, ether. Acetamidine hydrochloride is mainly used to synthesize vitamin B1, and can also be used to synthesize heterocyclic compounds such as pyridine and triazole or other chemical raw materials and intermediates. [0003] The synthesis of acetamidine hydrochloride was first reported by Pinner in 1877, using acetonitrile, absolute ethanol and dry hydrogen chloride gas to synthesize acetamidine hydrochloride, and acetamidine hydrochloride was obtained by ammonification of acetamidine with ethanol, and then Oxley and Short et al. A series of improvement studies have been carried out...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C257/14
CPCC07C257/14
Inventor 刘争平姜波鲁向阳
Owner 内蒙古益泽制药有限公司
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