反应详情

A solution of 2.7 g (10.4 mmol) of the oil from stage b) in 25 ml of methanol is treated with 1.5 g (20.8 mmol) of potassium carbonate and stirred at room temperature for 4 h. The salts are then filtered off and the filtrate is concentrated. The residue is purified by chromatography on silica gel (eluent: ethyl acetate/methanol/ammonia=19:1:0.4). 1.3 g (57%) of the title compound are isolated as a colorless oil which partially crystallizes after standing for a relatively long time. This product is employed directly for the further reaction (Example 15) without additional purification.

1. filtrationThe salts are then filtered off
2. concentrationthe filtrate is concentrated
3. customThe residue is purified by chromatography on silica gel (eluent: ethyl acetate/methanol/ammonia=19:1:0.4)