反应详情

The ester prepared in Example 13 (0.9 g, 2.3 mmol) was dissolved in ethanol (10 ml) and a 12 N sodium hydroxide solution (0.6 ml) was added. The reaction mixture was stirred at room temperature for 4 h. Concentrated hydrochloric acid solution (0.7 ml) was added with cooling of the reaction vessel in an ice-bath and dichloromethane (300 ml) was added. The resulting emulsion was dried over sodium sulphate and the solvent evaporated in vacuo to give an oily residue which was crystallised from acetone. This afforded 0.5 g (54%) of the title compound.

1. temperaturewith cooling of the reaction vessel in an ice-bath
2. dry with materialThe resulting emulsion was dried over sodium sulphate
3. customthe solvent evaporated in vacuo
4. customto give an oily residue which
5. customwas crystallised from acetone