反应详情

Methyl 3-bromo-6-bis-(tert-butoxycarbonyl)amino-2-(4-methylbenzenesulfonyl-oxy)benzoate (Intermediate 14, 6.2 g) was dissolved in methanol (200 mL) and 1M aqueous sodium hydroxide solution (50 mL) was added. The reaction mixture was stirred at room temperature for 30 minutes then the methanol was removed in vacuo and the residue was diluted with a mixture of ethyl acetate and water and then acidified with acetic acid. The layers were separated and the organic phase was dried (Na2SO4) and filtered. The filtrate was concentrated in vacuo to give methyl 3-bromo-6-bis-(tert-butoxycarbonyl)amino-2-hydroxybenzoate (4.51 g) as a sandy coloured solid.

1. customthe methanol was removed in vacuo
2. additionthe residue was diluted with a mixture of ethyl acetate and water
3. customThe layers were separated
4. dry with materialthe organic phase was dried (Na2SO4)
5. filtrationfiltered
6. concentrationThe filtrate was concentrated in vacuo