Boron tribromide → 3-(4-(2-Chlorophenyl)-9-hydroxy-1,3-dioxo-2,3-dihydropyrrolo[3,4-c]carbazol-6 (1H)-yl)-N-(2,2,6,6-tetramethyl-4-piperidinyl)propanamide

Participants

Reaction Steps

Demethylation of (124) prepared as described in example 237 with BBr3 using the procedure described in example 80 except that the reaction time was 48 h gave (125) as a yellow powder (47%), mp 293–299° C. (dec). 1H NMR δ [(CD3)2SO] 11.08 (br s, 1H), 9.38 (br s, 1H), 8.72 (br, 1H), 8.37 (d, J=2.4 Hz, 1H), 7.83 (d, J=7.1 Hz, 1H), 7.75 (s, 1H), 7.60–7.44 (m, 5H), 7.14 (dd, J=8.8, 2.4 Hz, 1H), 4.70 (t, J=5.8 Hz, 2H), 3.90 (m, 1H), 2.54 (t, J=5.8 Hz, 2H), 1.45–1.31 (m, 2H), 1.30 (s, 3H), 1.29 (s, 3H), 1.25 (s, 3H), 1.22 (s, 3H), 1.09–9.93 (m, 2H). Found: C, 58.67; H, 5.37; N, 8.41. C32H33ClN4O4.1.25CH2Cl2 requires C, 58.79; H, 5.27; N, 8.25.

Provenance & Evidence