反应详情

Demethylation of (816) prepared as described in example 416 with BBr3 using the procedure described in example 80 gave (817) (79%), mp 335–345° C. 1H NMR δ [(CD3)2SO] 11.77 (s, 1H), 11.04 (s, 1H), 9.23 (s, 1H), 8.24 (d, J=2.3 Hz, 1H), 7.75 (2d, J=8.2 Hz, 2H), 7.43 (d, J=8.7 Hz, 1H), 7.05 (dd, J=8.7, 2.3 Hz, 1H). Found: C, 64.44; H, 3.45; N, 10.41. C14H8N2O3.1/2H2O requires: C, 64.37; H, 3.47; N, 10.72.