反应详情

温度

0 °C

Isobutyl N-(5-chloro-3-methoxypyrazin-2-yl)carbamate (3.34 g) was added to a stirred suspension of sodium hydride (60% dispersion in oil; 0.56 g) in dry N, N dimethylformamide (20 ml) at 0° C. The mixture was stirred at 0° C. for 1 hour and then a solution of 2-iodobenzenesulphonyl chloride (obtained as described in J Org Chem, 1977, 42, 3265) (4.68 g) was added. The mixture was stirred for 2 hours and then volatile material was removed by evaporation. The residue was dissolved in water (50 ml) and the solution was acidified with 20% aqueous citric acid and extracted with ethyl acetate (3×20 ml). The extracts were washed with water (25 ml) and saturated sodium chloride solution (25 ml) and dried (MgSO4). Volatile material was removed by evaporation and the residue was purified by gradient elution with 10-35% ethyl acetatesohexane through a silica gel Mega Bond Elut column to give N-(5-chloro-3-methoxypyrazin-2-yl)- N-(isobutoxycarbonyl)-2-iodobenzenesulphonamide (2.64 g); 1H NMR (d6 -DMSO): 0.67 (s, 6H), 1.65-1.8 (m, 1H), 3.9 (d, 2H), 4.0 (s, 3H), 3.9 (s, 3H), 7.4 (dd, 1H), 7.8 dd, 1H), 8.2 (d, 1H), 8.3 (d, 1H), 8.4 (s, 1H).

1. stirringThe mixture was stirred for 2 hours
2. customvolatile material was removed by evaporation
3. dissolutionThe residue was dissolved in water (50 ml)
4. extractionextracted with ethyl acetate (3×20 ml)
5. washThe extracts were washed with water (25 ml) and saturated sodium chloride solution (25 ml)
6. dry with materialdried (MgSO4)
7. customVolatile material was removed by evaporation
8. customthe residue was purified by gradient elution with 10-35% ethyl acetatesohexane through a silica gel Mega Bond Elut column