1,1'-Carbonyldiimidazole → tert-Butyl 4-(2-oxo-1,2,3,4-tetrahydroquinazolin-6-yl)piperazine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of compound 17 (1.38 g, 4.5 mmol) in THF (20 mL) at room temperature was CDI (0.80 g, 4.95 mmol) and the reaction was stirred at 80° C. for 6 hr. The mixture was cooled to room temperature and the solid formed was filtered, washed with diethyl ether to afford 0.99 g (72%) of compound 10 as an off-white foam. IR (KBr) νmax. cm−1: 3210, 3162 (NH), 3032 (Ar—H), 1691 (C═O), 1607, 1515, 1419 (C═C). 1H NMR (500 MHz, CDCl3) δ=1.47 (s, 9H, (CH3)3C); 3.06 (m, 4H, 2CH2); 3.52 (m, 4H, 2CH2); 4.49 (s, 2H, CH2); 6.69 (m, 2H, aromatic-H), 6.74 (m, 1H, aromatic-H); 7.82 (br.s, 1H, NH); 13C NMR (125.7 MHz, CDCl3) δ=28.60 (CH3)3C), 43.35 (CH2), 43.90 (CH2), 50.66 (CH2), 80.10 (CH3)3C), 112.11 (aromatic-C), 112.28 (aromatic-C), 117.19 (aromatic-C), 130.18 (aromatic-C), 134.88 (aromatic-C), 143.18 (aromatic-C), 154.62 (CO), 155.93 (C═O). Calculated (%) for C17H24N4O3 (332.18); C, 61.43; H, 7.28; N, 16.86. found (%) C, 61.38; H, 7.32; N, 16.81.

Provenance & Evidence