反应 #657314

反应方程式

2-phenyl-6,7-dihydro-5H-pyrazolo[5,1-b][1,3]oxazine

bromine

sodium thiosulfate

→

3-bromo-2-phenyl-6,7-dihydro-5H-pyrazolo[5,1-b][1,3]oxazine

溶剂

chloroform

chloroform

反应条件

后处理

1. 1
   其他the phases are separated
2. 2
   洗涤the organic phase is washed with water
3. 3
   干燥dried over sodium sulfate
4. 4
   其他The volatiles are evaporated
5. 5
   过滤the crude product is purified by filtration over silica using
6. 6
   workup.ADDITIONa 1:1 mixture of ethyl acetate/cyclohexane as eluent
7. 7
   其他After evaporation of the solvent 7.0 g (90%) of 3-bromo-2-phenyl-6,7-dihydro-5H-pyrazolo[5,1-b][1,3]oxazine
8. 8
   其他are obtained as solid

实验过程

To a solution of 2-phenyl-6,7-dihydro-5H-pyrazolo[5,1-b][1,3]oxazine (6.3 g, 0.031 mol) in 60 mL chloroform is added a solution of bromine (1 eq, 5.03 g, 0.031 mol) in 40 mL chloroform over a period of 25 min at room temperature. The resulting suspension is stirred for 4 h at room temperature. Thereafter the reaction mixture is treated with aqueous sodium thiosulfate, the phases are separated and the organic phase is washed with water and dried over sodium sulfate. The volatiles are evaporated and the crude product is purified by filtration over silica using a 1:1 mixture of ethyl acetate/cyclohexane as eluent. After evaporation of the solvent 7.0 g (90%) of 3-bromo-2-phenyl-6,7-dihydro-5H-pyrazolo[5,1-b][1,3]oxazine are obtained as solid.

来源