反应详情

A mixture of 6-oxo-5,6,8,9-tetrahydro-7-oxa-5-aza-benzocycloheptene-3-carboxylic acid tert-butyl ester (1.1 g, 4.18 mmol), potassium carbonate (2.5 g, 18.1 mmol, 4.3 eq.) and iodoethane (1.67 mL, 20.87 mmol, 5 eq.) was stirred in DMF (20 mL) for 16 hours at 60° C. The reaction was diluted with water (50 mL) and extracted with ethyl acetate (3×20 mL). The combined organic layers were dried (sodium sulfate) and concentrated. Silica gel chromatography (0→20% ethyl acetate in hexanes) provided 5-ethyl-6-oxo-5,6,8,9-tetrahydro-7-oxa-5-aza-benzocycloheptene-3-carboxylic acid tert-butyl ester as pale solid in quantitative yield: 1H NMR (400 MHz, CDCl3) δ 7.81 (s, 1H), 7.80 (dd, 1H), 7.28 (d, 1H), 4.48 (t, 2H), 3.91 (q, 2H), 3.00 (t, 2H), 1.59 (s, 9H), 1.23 (t, 3H).

1. extractionextracted with ethyl acetate (3×20 mL)
2. dry with materialThe combined organic layers were dried (sodium sulfate)
3. concentrationconcentrated