1,1'-Carbonyldiimidazole → tert-Butyl 4-(2-oxo-1,2,3,4-tetrahydroquinazolin-7-yl)piperazine-1-carboxylate

Participants

Reaction Steps

Following the same procedure adopted for the synthesis of compound 13, reaction of compound 20 with CDI afforded 0.73 g (75%) of compound 16 as an off-white solid, m.p. 218-219° C.; IR (KBr) νmax. cm−1: 3211, 3166 (NH), 3037 (Ar—H), 1693 (C═O), 1610, 1519, 1417 (C═C). 1H NMR (500 MHz, CDCl3) δ=1.48 (s, 9H, (CH3)3C); 3.00 (m, 4H, 2CH2); 3.56 (m, 4H, 2CH2); 4.48 (s, 2H, CH2); 6.62 (d, 1H, J=2.5 Hz, H-8); 6.64 (d, 1H, J=8.5 Hz, H-5); 6.74 (dd, 1H, J=2.5, 8.4 Hz, H-6); 7.80 (br.s, 1H, NH); 13C NMR (125.7 MHz, CDCl3) δ=28.65 (CH3)3C), 43.31 (CH2), 43.98 (CH2), 50.63 (CH2), 80.18 (CH3)3C), 115.13 (C-8/C-6), 115.21 (C-8/C-6), 117.59 (C-5), 118.35 (C-5), 130.66 (C-5), 147.20 (C-5), 154.91 (C═O), 155.95 (C═O). Calculated (%) for C17H24N4O3 (332.18); C, 61.43; H, 7.28; N, 16.86. found (%) C, 61.37; H, 7.32; N, 16.80.

Provenance & Evidence