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Green new process for preparing tizanidine hydrochloride

A technology of tizanidine hydrochloride and new process is applied in the field of new process for preparing tizanidine hydrochloride, a pharmaceutical raw material, and can solve the problems of strong corrosion of equipment, complicated handling, environmental hazards and the like, and achieves reduction of production cost and reduced The effect of pollution and dosage reduction

Inactive Publication Date: 2011-08-03
CHANGZHOU YABANG PHARMA +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Among them, the two-step nitro reduction uses zinc powder and iron powder, or highly toxic hydrazine hydrate. Not only the reaction operation is complicated, the heat release is violent, and the material is easy to flush, but also the reaction will produce a large amount of iron sludge and zinc sludge. Cumbersome and very harmful to the environment
In addition, in the condensation reaction of 4-amino-5-chloro-2,1,3-benzothiadiazole and 1-acetylimidazoline, phosphorus oxychloride is used as a solvent, which is not only highly corrosive to equipment, but also Moreover, a large amount of acidic tail gas will be produced during the reaction process, which is extremely unfriendly to the human body and the environment

Method used

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  • Green new process for preparing tizanidine hydrochloride
  • Green new process for preparing tizanidine hydrochloride
  • Green new process for preparing tizanidine hydrochloride

Examples

Experimental program
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Effect test

Embodiment 1

[0022] Embodiment 1: the synthesis of 4-chloro o-phenylenediamine

[0023] Add 5L of ethanol and 2.5Kg of 4-chloro-2-nitroaniline into a 10L hydrogenation reactor, add 125g of 5% palladium carbon, then pass hydrogen three times to replace the air in the reactor, and heat up to 65-70 °C, keep the pressure inside the kettle at 2Mpa. After the reaction was complete as detected by TLC, the palladium carbon was filtered off, and the filter cake was washed twice with ethanol. The filtrate and washings were combined and concentrated to dryness under reduced pressure to obtain 1.88 Kg of 4-chloro-o-phenylenediamine with a yield of 91%.

Embodiment 2

[0024] Embodiment 2: the synthesis of 4-chloro o-phenylenediamine

[0025] Add 5L of ethanol and 2.5Kg of 4-chloro-2-nitroaniline into a 10L hydrogenation reactor, add 250g of Raney-Ni, then pass hydrogen three times to replace the air in the reactor, and raise the temperature to 65-70°C. Keep the pressure in the kettle at 2Mpa. After the reaction was detected by TLC, the Raney-Ni was filtered off, and the filter cake was washed twice with ethanol. The filtrate and washings were combined and concentrated to dryness under reduced pressure to obtain 1.96 Kg of 4-chloro-o-phenylenediamine with a yield of 95%.

Embodiment 3

[0026] Embodiment 3: the synthesis of 4-chloro o-phenylenediamine

[0027] Add 5L of methanol and 2.5Kg of 4-chloro-2-nitroaniline into a 10L hydrogenation reactor, add 125g of platinum oxide, then pass hydrogen three times to replace the air in the reactor, raise the temperature to 60-65°C, and keep The pressure in the kettle is 3.0Mpa. After the reaction was detected by TLC, the Raney-Ni was filtered off, and the filter cake was washed twice with ethanol. The filtrate and washings were combined and concentrated to dryness under reduced pressure to obtain 1.86 Kg of 4-chloro-o-phenylenediamine with a yield of 90%.

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Abstract

The invention relates to a green new process for preparing a bulk pharmaceutical chemical, namely tizanidine hydrochloride. The green new process comprises the following steps: taking 4-chlorine-2-nitraniline as raw material and carrying out catalytic hydrogenation and reduction, cyclization, nitration, catalytic hydrogenation and reduction, condensation and salification on the raw material so as to obtain the tizanidine hydrochloride. The green new process not only has simple post-processing, is simple to operate, greatly reduces pollution to environment and corrosion on device, reduces production cost and is more suitable for industrial production.

Description

technical field [0001] The invention relates to a preparation process of a pharmaceutical raw material drug, in particular to a new preparation process of a medical raw material drug tizanidine hydrochloride, which belongs to the field of drug synthesis. Background technique [0002] Tizanidine hydrochloride is a central skeletal muscle relaxant with an imidazoline structure developed by Novartis, Switzerland. It is used to reduce the increase in skeletal muscle tension caused by brain and spinal cord trauma, cerebral hemorrhage, encephalitis and multiple sclerosis. , muscle spasms and muscle stiffness and other diseases. This product can relieve spasticity, but does not cause muscle weakness, does not produce psychological dependence at a therapeutic dose, and is well tolerated. It is a central muscle relaxant with good clinical evaluation. The structural formula is shown below. [0003] [0004] [0005] The main method and route of bibliographical report synthetic...

Claims

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Application Information

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IPC IPC(8): C07D417/12
Inventor 陈再新王明林夏正君蒋龙张明光于鸿飞王勇军李小兵陶锋徐树行张志敏
Owner CHANGZHOU YABANG PHARMA
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