反应详情

To a solution of 2-methoxycarbonyl-3-chloro-5-methylthiophene (1.3 g, 6.8 mmol) in ethanol (16 mL) was added aqueous sodium hydroxide (1 N, 16 mL, 16 mmol) and the mixture stirred at ambient temperature. After 3 hours the mixture was concentrated of all volatiles in vacuo. The residual solid was dissolved in water (60 mL), acidified with 1 N HCl and the solid collected by filtration to afford 1.2 g (95% yield) of 2-carboxy-3-chloro-5-methylthiophene as a white solid; NMR (CDCl3) 6.8 (s, 1), 2.5 (s, 3) ppm.

1. concentrationAfter 3 hours the mixture was concentrated of all volatiles in vacuo
2. dissolutionThe residual solid was dissolved in water (60 mL)
3. filtrationthe solid collected by filtration