- Preparation method of penoxsulam original medicine related impurity bis-CHYMP
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The invention provides a preparation method of penoxsulam original medicine related impurity bis-CHYMP, which comprises the following steps of: 1, dissolving 2, 4-dichloro-5-methoxy pyrimidine in methanol, adding triethylamine, adding hydrazine hydrate, carrying out reflux reaction, monitoring the reaction by TLC until the reaction is completed, cooling to room temperature, purifying to obtain 2-chlorine-5-methoxy-4-hydrazinylpyrimidine; 2, dissolving 2-chlorine-5-methoxy-4-hydroxypyrimidine in methanol, adding triethylamine, slowly dropping 2, 4-dichloro-5-methoxy pyrimidine methanol solution, carrying out reflux reaction, detecting the reaction by LCMS until the reaction is completed, cooling to obtain mixed liquid; 3, extracting, washing and concentrating the mixed liquid, preparing high performance liquid phase and purifying to obtain 2-chlorine-4-[2-(2-chlorine-5-methoxy-4-pyrimidine base) hydrazino]-5-methoxy pyrimidine; the synthetic route is shown in the description. The methodhas the advantages of economic feasibility and high yield.
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Paragraph 0029-0031
(2019/03/24)
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- Process for the preparation of 2-amino-5, 8-dimethoxy (1,2,4) triazolo (1,5-c) pyrimidine
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2-Amino-5,8-dimethoxy[1,2,4]triazolo[1,5-c]-pyrimidine is prepared from a 5-chloro or 5-methoxy substituted 3-amino-8-methoxy[1,2,4]triazolo[4,3-c]-pyrimidine by reaction with methoxide in an alcohol solvent. Both rearrangement and, when the 5-substituent is chloro, methoxy substitution can be accomplished directly.
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- Process for the preparation of 2-amino-5,8-dimethoxy(1,2,4)triazolo(1,5c)pyrimidine
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2-Amino-5, 8-dimethoxy[1,2,4]triazolo[1,5-c]-pyrimidine is prepared from a 5-chloro or 5-methoxy substituted 3-amino-8-methoxy[1,2,4]triazolo[4,3-c]-pyrimidine by reaction with methoxide in an alcohol solvent. Both rearrangement and, when the 5-substituent is chloro, methoxy substitution can be accomplished directly.
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