反应详情

2-Butyl-5-(4-chlorophenyl)-4-hydroxyisothiazol-3(2H)-one 1,1-dioxide (0.9 g, ca. 60%, 1.71 mmol) was dissolved in DCM (50 mL). DMF (0.13 mL) was added. Under nitrogen atmosphere, oxalyl chloride (0.434 g, 3.42 mmol) was dropped in. The mixture was then heated to reflux for 2 h and then evaporated to dry. Water (30 mL) was added into the residue. It was then extracted with DCM (20 mL×3). The extracts were combined and washed with water (50 mL×3) and brine (20 mL), dried (MgSO4) and evaporated. The residue was then purified by column chromatography (ISOLUTE SI, 20 g/70 mL), eluting with DCM:heptane (25:75), to give the title compound (0.496 g, 87%); 1H NMR (400 MHz, CDCl3): δ 7.93 (d, 2H), 7.54 (d, 2H), 3.76 (t; 2H), 1.85-1.77 (m, 2H), 1.48-1.39 (m, 2H), 0.98 (t, 3H); 13C NMR (100 MHz, CDCl3): δ 155.8, 142.4, 139.0, 130.2, 129.9, 127.7, 121.8, 40.8, 30.2, 19.9, 13.4.

1. temperatureThe mixture was then heated
2. temperatureto reflux for 2 h
3. customevaporated
4. customto dry
5. additionWater (30 mL) was added into the residue
6. extractionIt was then extracted with DCM (20 mL×3)
7. washwashed with water (50 mL×3) and brine (20 mL)
8. dry with materialdried (MgSO4)
9. customevaporated
10. customThe residue was then purified by column chromatography (ISOLUTE SI, 20 g/70 mL)
11. washeluting with DCM:heptane (25:75)