Boron tribromide → 4-(2-Chlorophenyl)-9-hydroxy-1H-[1]benzothieno[3,2-e]isoindole-1,3(2H)-dione

Participants

Reaction Steps

Demethylation of (839) prepared as described in example 374 with BBr3 using the procedure described in example 80 except that the reaction time was 48 h gave (840) (65%) as a yellow solid, mp 311–313° C. 1H NMR δ [(CD3)2SO] 11.42 (s, 1H), 9.85 (s, 1H), 9.17 (d, J=2.5 Hz, 1H), 8.32 (s, 1H), 7.9 (d, J=9 Hz, 1H), 7.62 (m, 2H), 7.5 (m, 3H), 7.17 (dd, J=2.5, 9 Hz, 1H). MH+346. Found C, 68.75; H, 3.43; N, 3.89; S, 9.35. C20H11NO3S.0.2H2O requires: C, 68.83; H, 3.29; N, 4.01; S, 9.19.

Provenance & Evidence