Maleimide → 9-Methoxy-5-phenylpyrrolo[3,4-c]carbazole-1,3(2h,6h)-dione

Participants

Reaction Steps

Reaction of (818) prepared as described in example 418 with maleimide at 180° C. using the procedure described in example 69 gave the adduct (XCVIII; R=phenyl, R′═H) (819), which was used without further purification. The crude Diels-Alder adduct was aromatised with MnO2 using the procedure described in example 79 to give (820) (73%), mp 281–285° C. 1H NMR δ [(CD3)2SO] 11.63 (br s, 1H), 11.15 (br s, 1H), 8.45 (d, J=2.5 Hz, 1H), 7.78–7.76 (m, 2H), 7.68 (s, 1H), 7.65–7.62 (m, 2H), 7.57–7.53 (m, 2H), 7.22 (dd, J=8.8, 2.5 Hz, 1H), 3.89 (s, 3H). Found: C, 72.06; H, 4.57; N, 7.69. C21H14N2O3.1/3H2O requires: C, 72.41; H, 4.24; N, 8.04.

Provenance & Evidence