反应详情

Isobutyl chloroformate was added dropwise to a stirred solution of 2-iodo- N-(3-methoxy-5-methylpyrazin-2-yl)benzenesulphonamide (1.65 g), triethylamine (0.57 ml) and pyridine (0.16 ml) in dichloromethane (30 ml) under an atmosphere of argon. The mixture was stirred for 2 hours and then 2M hydrochloric acid (20 ml) was added. The organic layer was separated, washed with water (20 ml) and saturated sodium chloride solution and dried (MgSO4). Volatile material was removed by evaporation and the residue was purified by flash chromatography, eluting with ethyl acetateexane (1:4 v/v), to give 2-iodo- N-(isobutoxycarbonyl)- N-(3-methoxy-5-methylpyrazin-2-yl)benzenesulphonamide (2.0 g) as a gum; 1H NMR (d6 -DMSO): 0.7 (d, 2H), 1.6-1.8 (m, 1H), 2.5 (s, 3H), 3.9 (d, 2H), (dd, 1H), 8.35 (dd, 1H). 4.0 (s, 3H), 7.4 (dt, 1H), 7.7 (dr, 1H), 8.15 (s, 1H), 8.2 (dd, 1H), 8.35 (dd, 1H).

1. customThe organic layer was separated
2. washwashed with water (20 ml) and saturated sodium chloride solution
3. dry with materialdried (MgSO4)
4. customVolatile material was removed by evaporation
5. customthe residue was purified by flash chromatography
6. washeluting with ethyl acetateexane (1:4 v/v)