反应详情

温度

-20 °C

4-bromo-2-methoxyimino-3-oxobutyric acid (2.57 g) is added to methylene chloride (20 ml) and the solution is cooled to −20° C. Phosphorous pentachloride (2.5 g) is added in small lots over a period of 5 min while maintaining the temperature between −20° C. and −15° C. Thereafter, the temperature is slowly raised to −5° C. and the reaction mass is stirred at −5° C. to 0° C. until the starting material's absence is noted with TLC in about 30 mins. Aqueous workup was done to remove inorganic impurities and byproducts and the organic layer was dried over anhydrous sodium sulfate. This solution is taken as is for the next stage.

1. temperaturewhile maintaining the temperature between −20° C. and −15° C
2. temperatureThereafter, the temperature is slowly raised to −5° C.
3. customto remove inorganic impurities and byproducts
4. dry with materialthe organic layer was dried over anhydrous sodium sulfate