反应详情

温度

120 °C

A mixture of 3.0 g (11.7 mmol) of 4-fluoro-3-methoxyacetamidobenzoic acid and 2.1 g (5.2 mmol) of Lawesson's reagent was refluxed for 6 hours in 90 mL toluene, mixed with 1.0 g Lawesson's reagent and heated to 120° C. for another 6 hours. After the solvent was replaced with xylene, the mixture was heated to 180° C. for a further 8 hours in a pressurised vessel. Then the solvent was distilled off in vacuo, the crude product obtained was purified by flash chromatography (silica gel; ethyl acetate/petroleum ether=5:95), and evaporated down again. Yield: 2.1 g of yellow crystals (72% of theory); Rf value: 0.55 (silica gel; ethyl acetate/petroleum ether=3:7).

1. temperaturethe mixture was heated to 180° C. for a further 8 hours in a pressurised vessel
2. distillationThen the solvent was distilled off in vacuo