反应详情

3-(2,4-dichlorophenyl)propanoic acid (0.44 g, 2 mmol) in polyphosphoric acid (7 g) was heated to 100° C. under argon. After 90 min the mixture was cooled and treated with water (20 ml) and extracted with hexane (40 ml). The hexane layer was dried (MgSO4), and evaporated to dryness. The residue was purified by column chromatography on silica gel eluting with 0-30% dichloromethane in hexane to give the title product as a yellow solid, (0.018 g, 4.5%), δH (CDCl3) 2.8 (2H, m), 3.1 (2H, m), 7.6 (1H, d), 7.65 (1H, d).

1. temperatureAfter 90 min the mixture was cooled
2. extractionextracted with hexane (40 ml)
3. dry with materialThe hexane layer was dried (MgSO4)
4. customevaporated to dryness
5. customThe residue was purified by column chromatography on silica gel eluting with 0-30% dichloromethane in hexane