Chlorosuccinimide → 4-Chlorosampangine

Participants

Reaction Conditions

Reaction Steps

N-Chlorosuccinimide (200 mg, 1.5 mmol) was added to a suspension of sampan-gine (232 mg, 1.0 mmol) in DMF (10 mL) and the mixture stirred at 100° C. for 24 h. The reaction was then poured onto H2O (100 mL) and the solids isolated by filtration. The crude product was purified by column chromatography eluting with CHCl3 /EtOAc (9:1) to give 4-chlorosampangine (21) (142 mg, 53%). Crystallization from EtOAc provided an analytical sample: mp 262°-263° C.; IR (KBr) 1670, 1590, 1410, 1315, 1278, 1240, 1230, 1000, 790, 758, 725, 610 cm-1 ; 1H NMR (CDCl3) δ 7.68 (ddd, 1H, J=7.6, 7.6, 1.4 Hz), 7.81 (ddd, 1H, J=7.6, 7.6, 1.4 Hz), 7.95 (d, 1H, J=5.9 Hz), 8.41 (dd, 1H, J=7.6, 1.4 Hz), 8.76 (dd, 1H, J=7.6, 1.4 Hz), 8.93 (d, 1H, J=5.9 Hz), 9.09 (s, 1H); 13C NMR (CDCl3) 115.7 (1), 120.0 (0), 125.6 (1), 128.5 (1), 131.7 (1), 132.0 (0), 132.2 (0), 134.8 (1), 135.0 (0), 136.9 (0), 146.0 (0), 147.2 (1), 148.2 (1), 151.5 (0), 181.2 (0) ppm; Anal. calcd for C15H7ClN2O: C 67.56, H 2.65, N 10.50; found C 67.63, H 2.52, N 10.54.

Provenance & Evidence