反应 #657320

反应方程式

NH4OH

water

4-bromo-3-phenyl-1H-pyrazole-5-amine

1,1,3,3-tetramethoxypropane

→

3-bromo-2-phenylpyrazolo[1,5-a]pyrimidine

收率 76.6%

溶剂

acetic acid

反应条件

后处理

1. 1
   萃取extracted with dichloromethane (3×100 mL)
2. 2
   干燥The organic layer is dried over anhydrous magnesium sulphate
3. 3
   过滤filtered
4. 4
   浓缩concentrated under reduced pressure
5. 5
   其他The crude material is purified by column chromatography

实验过程

To a solution of 4-bromo-3-phenyl-1H-pyrazole-5-amine (5.0 g, 0.02 mol) in acetic acid (50 mL) is added 1,1,3,3-tetramethoxypropane (4.14 g, 0.025 mol). The mixture is stirred at 110° C. for 1 h. The reaction mixture is then poured into water, basified with NH4OH and extracted with dichloromethane (3×100 mL). The organic layer is dried over anhydrous magnesium sulphate, filtered and concentrated under reduced pressure. The crude material is purified by column chromatography using silica gel in dichloromethane and ethyl acetate (1:0 to 95:5) as eluent and 4.2 g (75%) of 3-bromo-2-phenylpyrazolo[1,5-a]pyrimidine are obtained as a beige solid.

来源