反应详情

温度

135 °C

2,3-Dichloroquinoxaline (3.5 g; 17.6 mmol; 1 eq), 4-(aminosulfonyl)-N,N-dimethylbenzamide (4 g; 17.6 mmol; 1 eq) and anhydrous K2CO3 (2.4 g; 17.6 mmol; 1 eq) are taken up in DMA (35 mL) and the resulting suspension is heated at 135° C. for 1 h. After evaporation of the DMA under reduced pressure, the reaction is stopped by addition of water (20 mL) then the suspension is acidified with a 25% aqueous solution of citric acid (70 mL). After overnight standing at 4° C., the yellow precipitate is filtered off, washed several times with water until pH=6 and dried under vacuum at 40° C. overnight affording 5.73 g of a yellow solid. It is taken up in EtOH (25 mL) and the suspension is heated for a few minutes. The precipitate is filtered off and washed twice with EtOH (10 mL) then dried under vacuum at 40° C. overnight to afford 3.96 g (57.6%) of the title compound as a yellow solid. 1H NMR (DMSO-d6) δ 8.27-8.24 (d, J=8.3 Hz, 2H), 7.91 (t, J=7.2 Hz, 2H), 7.79-7.74 (m, 2H), 7.73-7.66 (m, 3H), 3.02 (s, 3H), 2.88 (s, 3H). HPLC (max plot) 95%; Rt 3.18 min. LC/MS: (ES+): 391.3, (ES−): 389.2.

1. customAfter evaporation of the DMA under reduced pressure
2. additionthe reaction is stopped by addition of water (20 mL)
3. filtrationthe yellow precipitate is filtered off
4. washwashed several times with water until pH=6
5. customdried under vacuum at 40° C. overnight