[OH-].[K+].C(OC([N:8]1[C:14]2[CH:15]=[CH:16][C:17]([N+:19]([O-:21])=[O:20])=[CH:18][C:13]=2[O:12][CH2:11][CH2:10][CH2:9]1)=O)C>O.COCCO>[N+:19]([C:17]1[CH:16]=[CH:15][C:14]2[NH:8][CH2:9][CH2:10][CH2:11][O:12][C:13]=2[CH:18]=1)([O-:21])=[O:20]1.00 M of Potassium hydroxide in Water (38 mL) was added to 3-Nitro-7,8-dihydro-6H-5-oxa-9-aza-benzocycloheptene-9-carboxylic acid ethyl ester (1.967 g, 7.388 mmol) in 2-Methoxyethanol (80 mL) at 80° C. and further heated at 100° C. for 3 h. The solution was cooled and diluted with 200 mL water and was extracted with EtOAc (3×100 mL). The organic extract was washed with water (2×50 mL) and brine (100 mL), dried over sodium sulfate and concentrated to give 3-Nitro-6,7,8,9-tetrahydro-5-oxa-9-aza-benzocycloheptene as a yellow solid (1.34 g, 93%). 1H-NMR (CDCl3): 7.79 (s, 1H), 7.76 (d, 1H, J=8.8 Hz), 6.69 (d, 1H, J=8.8 Hz), 4.34 (s, 1H), 4.25 (t, 2H, J=5.9 Hz), 3.49 (m, 2H), 2.09 (m, 2H).
Loading…
