反应详情

A solution of 1,3-dibromo-5,5-dimethylhydantoin (1.375 kg. 4.81 moles) in acetonitrile (11.5 L) was added to a solution of methyl 3-(4-hydroxy-6-methyl-2-oxopyridin-1(2H)-yl)-4-methylbenzoate (5) (2.50 kg, 9.15 mol) in acetonitrile (4.8 L). The solution was added at a rate that maintained the temperature less than −10° C. for 90 to 180 minutes. A portion of the acetonitrile (approximately 6 L) was removed after completion of the reaction via distillation. The product was precipitated by the addition of water (7.9 L) and filtered to yield 2.90 kg (90%) of methyl 3-(3-bromo-4-hydroxy-6-methyl-2-oxopyridin-1(2H)-yl)-4-methylbenzoate (4)

1. additionThe solution was added at a rate that
2. temperaturemaintained the temperature less than −10° C. for 90 to 180 minutes
3. customA portion of the acetonitrile (approximately 6 L) was removed
4. customafter completion of the reaction
5. distillationvia distillation
6. customThe product was precipitated by the addition of water (7.9 L)
7. filtrationfiltered