反应详情

3-Bromo-5-tert-butylbenzoic acid (5 g) was dissolved in THF (180 ml), and n-butyllithium (18.7 ml, 2.5 M in hexane) was added dropwise under argon and at −75° C., and stirred for a further 30 min. Then trimethyl borate (6.63 ml) was added dropwise and the mixture was allowed to come to RT within 1 h. Thereafter, sodium hydroxide (0.778 g), dissolved in 2 ml of water, and hydrogen peroxide (12.89 ml, 30%) were added in succession. After stirring at RT for 3 h, the mixture was left to stand over the weekend. Then water and EA were added, the mixture was adjusted to pH 3 with 1 N hydrochloric acid and the EA phase was removed. This phase was washed three times with water, dried, filtered and concentrated. The residue was purified using silica gel (120 g cartridge, n-heptane/MtB ether gradient of 0-50% in 60 min). 1.94 g of the title compound were obtained.

1. waitto come to RT within 1 h
2. stirringAfter stirring at RT for 3 h
3. waitthe mixture was left
4. customthe EA phase was removed
5. washThis phase was washed three times with water
6. customdried
7. filtrationfiltered
8. concentrationconcentrated
9. customThe residue was purified
10. customsilica gel (120 g cartridge, n-heptane/MtB ether gradient of 0-50% in 60 min)