反应详情

8-(Benzyloxy)-7-methoxy-2,3-dihydroimidazo[1,2-c]quinazolin-5-amine (Intermediate A, Step 7, 21 g, 65 mmol) and nicotinic acid (12 g, 97.7 mmol) were suspended in DMF (240 mL). Diisopropylethylamine (33.7 g, 260.4 mmol) and then PyBOP (51 g, 97.7 mmol) were added and the resulting mixture stirred with overhead stirring for 3 days at ambient temperature. At this time, the resultant precipitate was isolated by vacuum filtration. After repeated washing with EtOAc, the material was dried under vacuum with slight heating to yield the title compound (27.3 g, 98%): HPLC MS RT=1.09 min, MH+=481.2; 1H NMR (DMSO-d6+2 drops TFA-d) δ: 9.32 (1H, s), 8.89 (1H, br m), 8.84 (1H, d), 7.89 (1H, br m), 7.82 (1H, d), 7.37 (1H, d), 7.27 (1H, d), 7.16 (6H, m), 5.18 (2H, s), 4.36 (2H, t), 4.04 (2H, t), 3.78 (3H, s).

1. stirringstirring for 3 days at ambient temperature