反应详情

Dicyclohexyicarbodiimide (1.20 Kg, 5.8 mol, 1.1 eq) was added portionwise over 4.5 hours to a cooled, mechanically-stirred slurry of 2-hydroxy-1-naphthoic acid (1.00 Kg, 5.3 mol) in methanol (3 L) under nitrogen. The internal temperature was maintained between 10 and 15° C. during the addition. Once the addition was complete, the mixture was allowed to warm to ambient temperature and stirred for 16 hours. The methanol was removed under reduced pressure and the residue taken up in ethyl acetate (5 L) and heated with stirring to 64° C. (internal temperature) and then allowed to cool once again to ambient temperature. The mixture was filtered, and the solid washed with ethyl acetate (0.7 L). The ethyl acetate solutions were combined and concentrated under reduced pressure. The residue (2.5 Kg) was recrystallised from ethanol-water (9:1, 3.3 L) and dried under vacuum at ambient temperature. Yield 0.92 Kg, 85%

1. temperatureThe internal temperature was maintained between 10 and 15° C. during the addition
2. additionOnce the addition
3. customThe methanol was removed under reduced pressure
4. temperatureheated
5. stirringwith stirring to 64° C. (internal temperature)
6. temperatureto cool once again to ambient temperature
7. filtrationThe mixture was filtered
8. washthe solid washed with ethyl acetate (0.7 L)
9. concentrationconcentrated under reduced pressure
10. customThe residue (2.5 Kg) was recrystallised from ethanol-water (9:1, 3.3 L)
11. customdried under vacuum at ambient temperature