[NH2:1][C:2]1[CH:13]=[CH:12][C:5]2[N:6]=[C:7](SC)[CH2:8][O:9][C:4]=2[C:3]=1[C:14]([O:16][CH3:17])=[O:15].[CH3:18][O:19][CH:20]([O:23][CH3:24])[CH2:21][NH2:22]>C(O)C>[NH2:1][C:2]1[CH:13]=[CH:12][C:5]2[N:6]=[C:7]([NH:22][CH2:21][CH:20]([O:23][CH3:24])[O:19][CH3:18])[CH2:8][O:9][C:4]=2[C:3]=1[C:14]([O:16][CH3:17])=[O:15]A solution of methyl 7-amino-3-methylsulfanyl-2H-benzo[1,4]oxazine-8-carboxylate (Intermediate 28, 0.645 g) and aminoacetaldehyde dimethylacetal (0.403 g) in ethanol (15 mL) was heated to reflux for 4 days. After cooling, the mixture was concentrated in vacuo to give methyl 7-amino-3-(2,2-dimethoxyethylamino)-2H-benzo[1,4]oxazine-8-carboxylate (0.910 g) as a brown oil.
Loading…