反应详情

A solution of 1,3-dibromo-5,5-dimethylhydantoin (65 g) in DCM (150 mL) was added dropwise to a stirred and cooled solution of methyl 6-methyl-2-oxocyclohex-3-enecarboxylate (prepared in a similar manner to Hauser et al, Synthesis 1980 814, 75.16 g) and N,N-di-isopropylamine (6.15 mL) in DCM (500 mL) at 0° C. and the resultant mixture was stirred at room temperature for 3 days. The mixture was recooled to 0° C. and further 1,3-dibromo-5,5-dimethylhydantoin (11 g) was added and the mixture was stirred at 0° C. for 3 hours. The precipitate was removed by filtration and the filtrate was evaporated to dryness to give methyl 3-bromo-2-hydroxy-6-methylbenzoate (114.5 g) as an oil.

1. customwas recooled to 0° C.
2. stirringthe mixture was stirred at 0° C. for 3 hours
3. customThe precipitate was removed by filtration
4. customthe filtrate was evaporated to dryness