Preparation process of intermediate 2-cyanpyrazine of pyrazinamide drug

A technology of pyrazinamide and cyanopyrazine, applied in the direction of organic chemistry, etc., can solve the problems of harsh conditions, high temperature and high pressure conditions, complicated post-processing, etc., and achieve the effect of simple feeding and post-processing, and less pollution

Inactive Publication Date: 2007-05-16
ZHEJIANG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The preparation of catalysts in the above synthesis processes is complex, the reaction process cycle time is long, the conditions are harsh, or many experimental processes involve high temperature and high pressure conditions, low yield, complex post-processing and other problems

Method used

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  • Preparation process of intermediate 2-cyanpyrazine of pyrazinamide drug
  • Preparation process of intermediate 2-cyanpyrazine of pyrazinamide drug
  • Preparation process of intermediate 2-cyanpyrazine of pyrazinamide drug

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] In a 1000 ml three-necked flask, 500 ml of N,N-dimethylacetamide solvent, 48 g (300 mmol) of 2-bromopyrazine, 25 g (60 mmol, 0.2 equivalents) of tris Potassium ferrocyanide hydrate, 680 milligrams (3 millimoles, 0.3mol%) palladium acetate catalyst, 35 grams of sodium carbonate (330 millimoles, 1.1 equivalents), under nitrogen protection at 120 ℃ stirring reaction 2 hours, finish reaction, Then filtered, the filtrate was fractionated under reduced pressure to obtain transparent liquid 2-cyanopyrazine, boiling point: 84-87°C (18-20mmHg), yield 88%, purity 98% (GC).

Embodiment 2

[0020] In a 1000 ml three-necked flask, 500 ml of N,N-dimethylacetamide solvent, 48 g (300 mmol) of 2-bromopyrazine, 28 g (66 mmol, 0.22 equivalent) of tris Potassium ferrocyanide hydrate, 340 milligrams (15 millimoles, 5mol%) palladium acetate catalyst, 31.8 gram sodium carbonates (300 millimoles, 1.0 equivalents), under nitrogen protection, stirred reaction at 100 ℃ for 13 hours, ended the reaction, then After filtration, the filtrate was fractionated under reduced pressure to obtain transparent liquid 2-cyanopyrazine with a yield of 90% and a purity of 99%.

Embodiment 3

[0022] In a 1000 ml three-necked flask, 500 ml of N,N-dimethylacetamide solvent, 48 g (300 mmol) of 2-bromopyrazine, 20 g (45 mmol, 0.15 equivalent) of tris Sodium ferrocyanide hydrate, 1.5 millimoles (0.5mol%) two (dibenzylidene pyruvate) palladium catalysts, 31.8 grams of sodium carbonate (300 millimoles, 1.0 equivalent), under nitrogen protection, at 120 ℃ stirring reaction 4 Hours, the reaction was terminated, followed by filtration, and the filtrate was fractionated under reduced pressure to obtain a transparent liquid 2-cyanopyrazine with a yield of 80% and a purity of 99%.

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Abstract

The invention discloses a manufacturing technique of 2-cyano pyrazine as pyrazine amide medicinal intermediate, which comprises the following steps: adopting N, N-dimethyl acetamide as reacting solvent and 0.1-5% palladium complex as catalyst; making 0.5-2% alkaline metal carbonate as alkaline; reacting 2-cyano pyrazine and alkaline metal ferrocyanide with molar rate at 1: 0.15-0.3 protected by nitrogen under 100-150 Deg C for 1-6h; filtering; decompressing the filtrate; fractioning to obtain the 2-cyano pyrazine. The invention shortens reacting flow path, which is easy to feed and dispose without poison in the whole course.

Description

technical field [0001] The invention relates to a preparation method of a pharmaceutical intermediate, in particular to a production process of a pyrazinamide drug intermediate 2-cyanopyrazine. Background technique [0002] 2-cyanopyrazine is an important raw material for the production of pyrazinamide, a drug for treating tuberculosis. Therefore, how to efficiently synthesize 2-cyanopyrazines has attracted great attention. The synthesis of 2-cyanopyrazine has been reported in some literatures. For example, the literature "Fine Chemical Industry" reported the research on the preparation of 2-cyanopyrazine by ammoxidation of 2-methylpyrazine with a special catalyst. The literature Applied Catalsis, 1986, 20: 219-222 reported that ethylenediamine and propylene glycol were cyclized and dehydrated to 2-methylpyrazine under the action of a catalyst, and then catalyzed by high temperature and high pressure for ammoxidation to 2-cyanopyrazine. The document CN1398855 reports that ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D241/24
Inventor 林旭锋徐方羲
Owner ZHEJIANG UNIV
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