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196806-10-7

Temozolomide Impurity synthesis

2synthesis methods
-

Yield:196806-10-7 92%

Reaction Conditions:

Stage #1: 5-Aminoimidazole-4-carboxamidewith triethylamine in dichloromethane at 25; for 0.166667 h;
Stage #2: 4-Nitrophenyl chloroformate in dichloromethane at 25; for 22 h;

Steps:

A Preparation of Step A Intermediate 2

To a 5 L three-necked round bottom flask equipped with a thermometer, 5-aminoimidazole-4-carboxamide A (80 g, 634.32 mmol), dichloromethane (1920 mL), triethylamine (176.82 mL, 1268.63 mmol), After stirring at 25 ° C for 10 minutes, the temperature of the reaction system was lowered to below 0 ° C. After 10 minutes, 4-nitrophenyl chloroformate (255.71 g, 1268.36 mmol) dissolved in 1280 mL of dichloromethane was added dropwise. After reacting for 4 hours at 0 ° C or lower, the temperature was controlled at 25 ° C for 18 hours. The reaction solution was suction filtered with a Buchner funnel, and the obtained cake was washed with 1000 mL of dichloromethane and 200 ml of water for 1 hour, and filtered again. The filter cake was washed with dichloromethane and dried at room temperature to obtain a yellow solid product. . Yield: 92%, melting point: decomposition at 200 ° C.

References:

CN103626772,2016,B Location in patent:Paragraph 0006; 0009; 0027; 0028-0031

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