反应详情

温度

0 °C

Chlorosulfonic acid (36.59 mL, 550.5 mmol) was cooled to 0° C. under argon atmosphere. The cooled chlorosulfonic acid was added dropwise to compound 4.2 (24.5 g, 110.1 mmol) using a dropping funnel. The reaction was stirred at 0° C. for 30 min. and at room temperature for 4 h. The reaction mixture was poured into ice-water and stirred slowly at 0° C. for 20 min. The precipitated crystals were collected and dried in vacuo using oven at 40° C. to give 4.3 (30.8 g) as pale-yellow crystals. 1H NMR (300 MHz) (CDCl3) δ 7.90-7.79 (2H, m); 6.81 (1H, d, J=8.4 Hz); 4.75 (2H, s); 4.28 (2H, q, J=7.1 Hz); 2.79-2.67 (2H, m); 1.77-1.60 (2H, m); 1.30 (3H, t, J=7.1 Hz); 0.97 (3H, t, J=7.3 Hz).

1. stirringstirred slowly at 0° C. for 20 min
2. customThe precipitated crystals were collected
3. customdried in vacuo
4. customat 40° C.