反应详情

To a stirred solution of sodium acetate (19.7 g., 0.24 mole) in acetic acid (100 ml.) and water (15 ml.), 3-isopropylpyrazole (11.0 g., 0.1 mole) was added, followed by dropwise addition of bromine (16.0 g., 0.11 mole) keeping the internal temperature below 15° C. The mixture was kept at 25° C. for 15 hours, treated with water (200 ml.) and extracted with ethyl ether (3 × 50 ml.), and the ether layer washed with water (1 × 50 ml.) dried, (sodium sulfate) and evaporated under reduced pressure. The resultant pale yellow oil was distilled to give 4-bromo-3-isopropylpyrazole (15.3 g., 81%) with a boiling point of 85° C. at 0.06 mm Hg.

1. customthe internal temperature below 15° C
2. extractionextracted with ethyl ether (3 × 50 ml.)
3. washthe ether layer washed with water (1 × 50 ml.)
4. customdried
5. custom(sodium sulfate) and evaporated under reduced pressure
6. distillationThe resultant pale yellow oil was distilled