反应详情

A mixture of 4-(2,6-difluoro-benzoylamino)-1H-pyrazole-3-carboxylic acid ethyl ester (10.2 g) in 2 M aqueous NaOH/MeOH (1:1, 250 ml) was stirred at ambient temperature for 14 h. Volatile materials were removed in vacuo, water (300 ml) added and the mixture taken to pH 5 using 1M aqueous HCl. The resultant precipitate was collected by filtration and dried through azeotrope with toluene to afford 4-(2,6-difluoro-benzoylamino)-1H-pyrazole-3-carboxylic acid as a pink solid (5.70 g). (LC/MS: Rt 2.33, [M+H]+ 267.96).

1. customVolatile materials were removed in vacuo, water (300 ml)
2. additionadded
3. filtrationThe resultant precipitate was collected by filtration
4. dry with materialdried through azeotrope with toluene