反应详情

To 1 g of 2-(4-cyanomethylphenoxy)-3-pyridylacetic acid was added 20 g of polyphosphoric acid, and the mixture was stirred in an oil bath at 151°-152° C. for 2.5 hours. After cooling, to this was ice water to decompose excess polyphosphoric acid, and the mixture was basified with a 10% sodium hydroxide solution and extracted with ethyl acetate. The extract was washed with water and then a saturated sodium chloride solution and dried over anhydrous sodium sulfate. The solvent was removed by distillation to obtain a solid, which was chromatographed over 20 g of silica gel and eluted with n-hexane/acetone (2/1-1/1) to obtain crystals. These were recrystallized from acetone to give 300 mg (yield: 30%) of (5,6-dihydro-6-oxo benzo[b]pyrido-[3,2-f]oxepin-8-yl)-acetamide as white needle crystals having a melting point of 214°-217° C.

1. extractionextracted with ethyl acetate
2. washThe extract was washed with water
3. dry with materiala saturated sodium chloride solution and dried over anhydrous sodium sulfate
4. customThe solvent was removed by distillation
5. customto obtain a solid, which
6. customwas chromatographed over 20 g of silica gel
7. washeluted with n-hexane/acetone (2/1-1/1)
8. customto obtain crystals
9. customThese were recrystallized from acetone