反应详情

3-(2,5-Dimethyl-pyrrol-1-yl)-6-methoxy-5-trifluoromethyl-pyridine-2-carboxylic acid (Intermediate D2)(500 mg, 1.591 mmol) in methanol (15.91 ml) was treated with H2SO4 (0.0424 ml, 0.795 mmol) and the solution was heated at reflux for overnight. The solvent removed was removed in vacuo and the resulting brown oil was neutralised to pH 7 using saturated sodium bicarbonate. The mixture was extracted with EtOAc (20 ml) and the combined organic extracts were washed with water (20 ml), brine (20 ml), passed though a phase separator and concentrated in vacuo. Purification of the crude product by chromatography on silica eluting with iso-hexane: EtOAc (gradient of 0 to 10% EtOAc) afforded the title compound as an off-white powder.

1. temperaturethe solution was heated
2. temperatureat reflux for overnight
3. customThe solvent removed
4. customwas removed in vacuo
5. extractionThe mixture was extracted with EtOAc (20 ml)
6. washthe combined organic extracts were washed with water (20 ml), brine (20 ml)
7. concentrationconcentrated in vacuo
8. customPurification of the crude product by chromatography on silica eluting with iso-hexane