Yield:7335-65-1 90.5%

Reaction Conditions:

with hydrazine hydrate at 0 - 20; for 0.666667 h;

Steps:

1 Hydrazine acetate (Intermediate 1)
in 100ml of round bottom flask add 85% of Hydrazine hydrate(28. 5ml, 0. 5mol), ice bath with stirring and was slowly added dropwise ice acetic acid(28.6ml0. 5mol) to control the temperature at 0-10 ° C. After the completion ofthe dropwise addition the reaction mixturewas stirred at room temperature for 40min. After distillation under reducedpressure to remove water, in the remaining liquid add Chloroform: ethanol (1:1,20ml), in the ice bath was stirred forcrystallization, and then placed in 4 ° C refrigerator for further crystallization then evaporated to dryness under reduced pressureto give a white solid (41. 6g, 90. 5%).

References:

Shanghai Institute of Pharmaceutical Industry;Shen, Shunyi;Yuan, Fang;Ge, Han;Zhang, Zhihong;Liu, Yubin CN102786570, 2016, B Location in patent:Paragraph 0074; 0075

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