反应详情

A mixture of 4-iodopyrazole (1.000 g, 5.155 mmol), Cs2CO3 (2.016 g, 6.186 mmol) and DMF (20 mL, 0.2 mol) was added chloroacetic acid methyl ester (0.5440 mL, 6.186 mol) at 0° C. The reaction was allowed to stir for 1 h at rt. The material was transferred to a separatory funnel, diluted with EtOAc, and washed with water several times to remove DMF. The organic layer was dry-loaded onto silica gel, and column chromatography was used to purify, eluting with 3:1 Hexanes/EtOAc, affording the title compound as a clear liquid. 1H NMR (400 MHz, CDCl3): δ=3.79 (s, 3H), 4.93 (s, 2H), 7.54 (s, 1H), 7.57 (s, 1H). MS (ES+): m/z=266.95 (100) [MH+]. HPLC: tR=2.73 min (ZQ3, polar—5 min).

1. customThe material was transferred to a separatory funnel
2. washwashed with water several times
3. customto remove DMF
4. customto purify
5. washeluting with 3:1 Hexanes/EtOAc