Hydrochloric Acid → 4-(5-amino-2-methoxyphenyl)-9-hydroxypyrrolo[3,4-c]carbazole-1,3(2H,6H)-dione

Participants

Reaction Conditions

Reaction Steps

To a solution of 9-hydroxy-4-(2-methoxy-5-nitrophenyl)pyrrolo[3,4-c]carbazole-1,3(2H,6H)-dione (VI; Ar=2-methoxy-5-nitrophenyl, R10═H) (38) (64 mg, 0.159 mmol) prepared according to example 72 in methanol (10 mL) and THF (1 mL) was added 2N HCl (1 mL) Freshly prepared nickel boride (˜0.50 g) was added and the mixture was warmed at 60° C. After 1 h HCl (1 mL) and Ni2B (−0.50 g) were added and the reaction mixture was maintained at 60° C. a total of 4 h. The solvents were removed in vacuo and the residue was partitioned between ethyl acetate and 2N HCl. The aqueous layer was basified with conc. ammonia solution and extracted with ethyl acetate. The organic phase was dried, the drying agent was removed and the solvent concentrated to dryness gave a solid which when crystallised from THF/petroleum ether gave 4-(5-Amino-2-methoxyphenyl)-9-hydroxypyrrolo[3,4-c]carbazole-1,3(2H,6H)-dione (VI; Ar=5-amino-2-methoxyphenyl, R10═H (39) in a yield of 49.7 mg, 84% as a yellow powder; mp 246–250° C. 1H NMR δ [(CD3)2SO] 11.67 (s, 1H), 10.87 (s, 1H), 9.21 (s, 1H), 8.30)d, J=2.4 Hz, 1H), 7.44 (s, 1H), 7.42 (d, J=8.7 Hz, 1H), 7.05 (dd, J=8.6, 2.5 Hz, 1H), 6.80 (d, J=8.7 Hz, 1H), 6.61 (dd, J=8.6, 2.7 Hz, 1H), 6.55 (d, J=2.8 Hz, 1H), 4.68 (br, 2H), 3.53 (s, 3H). FABMS found [M+H]+: 373.1056. C21H15N3O4 requires 373.1062.

Provenance & Evidence