反应详情

A mixture of 1e from Example 19 (5 g, 24.5 mmol), 3-iodobenzoic acid (6.69 g, 27 mmol), potassium carbonate (3.79 g, 27.5 mmol) and a catalytic amount of copper-bronze in 30 ml dry N-methyl-2-pyrrolidone is heated to 180° C. overnight. After cooling water is added and the mixture is washed twice with ethyl acetate. The aqueous phase is rendered acidic with diluted hydrochloric acid and the oily precipitate is filtered off. This precipitate is extracted with ethyl acetate, and the extract is purified by column-chromatography on silica gel using a mixture of ethyl acetate and petroleum ether (1:1) as the eluent. Yield: 2.56 g (32%). Mp 203-205° C.

1. additionis added
2. washthe mixture is washed twice with ethyl acetate
3. filtrationthe oily precipitate is filtered off
4. extractionThis precipitate is extracted with ethyl acetate
5. customthe extract is purified by column-chromatography on silica gel using
6. additiona mixture of ethyl acetate and petroleum ether (1:1) as the eluent