反应详情

To a suspension of oxamic acid (1.76 g, 20 mmol) in 1,2-dimethoxyethane (75 mL) under an argon atmosphere was added dropwise N-methylmorpholine (2.55 mL, 23 mmol) followed by ethyl chloroformate (2.20 mL, 23 mmol). After stirring for 1 h at room temperature, a solution of 2-(3-cyclopentyloxy-4-methoxy-phenyl)ethylamine (4.65 g, 20 mmol) in 1,2-dimethoxyethane (30 mL) was added over 5 min, and the resulting mixture was stirred for 2 h. Saturated aqueous ammonium chloride was added and the solvent was removed under reduced pressure. The solid residue was dissolved in methanol/methylene chloride, washed successively with water, 10% hydrochloric acid, aqueous sodium bicarbonate and water and dried (potassium carbonate). The solvent was removed in vacuo and the residue was purified by flash chromatography, eluting with 1% i-propanol/methylene chloride to provide the oxamide (1.82 g, 30%): m.p. 175°-175.5° C.

1. stirringthe resulting mixture was stirred for 2 h
2. customthe solvent was removed under reduced pressure
3. dissolutionThe solid residue was dissolved in methanol/methylene chloride
4. washwashed successively with water, 10% hydrochloric acid, aqueous sodium bicarbonate and water
5. dry with materialdried (potassium carbonate)
6. customThe solvent was removed in vacuo
7. customthe residue was purified by flash chromatography
8. washeluting with 1% i-propanol/methylene chloride