- Synthesis process of 2-(5-amino-1,2,4-thiadiazol-3-yl)-2-(methoxyimino)acetic acid
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The invention relates to a synthesis process of 2-(5-amino-1,2,4-thiadiazol-3-yl)-2-(methoxyimino)acetic acid. With cyanoacetamide serving as a starting material, 2-(5-amino-1,2,4-thiadiazol-3-yl)-2-(methoxyimino)acetic acid is obtained through a hydroxyl oximation reaction, a methylation reaction, a cyclization reaction, a nitrile hydrolysis reaction and the like. Particularly, due to the fact that hydroxyapatite is added in the fifth step to serve as a catalyst, the yield of the intermediate product 2-(5-amino-1,2,4-thiadiazol-3-yl)-2-(methoxyimino)acetonitrile and the total yield of the final product 2-(5-amino-1,2,4-thiadiazol-3-yl)-2-(methoxyimino)acetic acid can be effectively increased, and compared with the total yield not exceeding 9% in the prior art, the total yield of the technical scheme reaches 13% or so and is substantially increased; cost is lowered; industrial large-scale application is facilitated.
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Paragraph 0027
(2017/01/02)
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- Process for the preparation of 2-cyano-2-oximino-acetamide derivatives
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A process for the preparation of a 2-cyano-2-oximino-acetamide derivative of the formula STR1 in which RI is alkyl or other organic radical, RII is hydrogen or alkyl, RIII is hydrogen, alkyl or other organic radical which comprises reacting a 2-cyano-2-oximino-acetamide of the formula STR2 with a base B at a temperature between 0° C. and 100° C., to produce a salt of the formula STR3 in which B represents one equivalent of an organic of inorganic base, and reacting such salt with an alkylating agent of the formula STR4 in which X is halogen, methane- or p-toluenesulphonate or methyl sulphate, at a temperature between 0° C. and 150° C.
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