反应详情

N,N′-dicyclohexylcarbodiimide (2.48 g, 0.012 mol) was added to chilled (0° C.) 3-(4-hydroxyphenyl)propanoic acid solution (2 g, 0.012 mol) and 4-nitrophenol (1.95 g, 0.014 mol) in ethyl acetate (25 cm3) and mixed magnetically at 0° C. for 30 min. The reaction mixture was then stirred magnetically for 2 h at room temperature. Thereafter, the precipitated N,N′-dicyclohexylureaa was filtered out, washed using ethyl acetate (5 cm3) and the combined filtrates were evaporated until dry. Anhydrous methanol saturated with ammonia (10 cm3) was added and the reaction mixture was stirred magnetically for 2 hrs, thereafter the mixture was evaporated until dry, and the remainder was loaded onto a chromatography column packed with Merck 60H silica gel (5-40 μm). The column was eluted with chloroform-methanol (50:1, v/v). The chromatographically purified product was crystallized out of the methanol and then vacuum desiccated over phosphorus pentocide yielding 1.45 g 3-(4-hydroxyphenyl)propanoic acid amide (75% efficiency) (FIG. 1).

1. additionmixed magnetically at 0° C. for 30 min
2. filtrationThereafter, the precipitated N,N′-dicyclohexylureaa was filtered out
3. washwashed
4. customthe combined filtrates were evaporated
5. customuntil dry
6. additionAnhydrous methanol saturated with ammonia (10 cm3) was added
7. stirringthe reaction mixture was stirred magnetically for 2 hrs
8. customthe mixture was evaporated
9. customuntil dry
10. washThe column was eluted with chloroform-methanol (50:1
11. customThe chromatographically purified product was crystallized out of the methanol