反应详情

To a suspension of Na2CO3 (13 g, 124 mmol) in CH2OH2 (100 mL) was added 1-cyclopentyl-1 H-pyrazole (8.35 g, 62 mmol) and Br2 (3.2 mL). The resulting mixture was stirred at RT overnight. The solid was removed by filtration and the filter cake was washed with DCM. The combined filtrates were washed with water, brine and dried over anhydrous MgSO4. The solvent was concentrated to dryness to give 4-bromo-1-cyclopentyl-1 H-pyrazole (14 g, 93%). 1H NMR (300 MHz, CDCl3): δ7.46 (s, 1 H), 7.44 (s, 1 H), 4.64 (m, 1 H), 2.18-1.67(m, 8 H); MS (ESI) m/z: 215.0 [M+H]+.

1. customThe solid was removed by filtration
2. washthe filter cake was washed with DCM
3. washThe combined filtrates were washed with water, brine
4. dry with materialdried over anhydrous MgSO4
5. concentrationThe solvent was concentrated to dryness