反应详情

This compound was prepared by General Method 3 (EXAMPLE 1) from 3-ethyl-3,4-dihydro-7-nitro-2H-1,4-benzoxazine (EXAMPLE 42) (200 mg, 0.96 mmol), acetaldehyde (424 mg, 9.6 mmol) and NaBH3CN (293 mg, 4.6 mmol) to afford 170 mg (75%) of (±)-3,4-diethyl-3,4-dihydro-7-nitro-2H-1,4-benzoxazine, a yellow solid. Data for (±)-3,4-diethyl-3,4-dihydro-7-nitro-2H-1,4-benzoxazine: Rf 0.80 (3:2 EtOAc:hexanes); 1H NMR (500 MHz, CDCl3) δ 7.80 (dd, 1H, J=8.9, 2.6), 7.66 (d, 1H, J=2.6), 6.55 (d, 1H, J=9.2), 4.07 (dd, ABX, 1H, J=10.7, 2.5), 3.96 (dd, ABX, 1H, J=10.7, 2.6), 3.60 (m, 1H), 3.55-3.35 (m, 2H), 1.29 (d, 3H, J=6.6), 1.24 (t, 3H, J=7.0).