反应详情

Boron tribromide (285 mL, 1 M, 0.285 mol) in DCM was added over 45 min to a solution of tert-butyl 7-methoxy-3,4,4a,9a-tetrahydro[1]benzofuro[2,3-c]pyridine-2(1H)-carboxylate (33.3 g, 0.11 mol) in DCM (1.2 L). The reaction mixture was kept at 5-8° C. using a water bath cooling. After 1 h stirring, H2O (250 mL) and NaOH (350 mL, 3 M) were added, followed by di-tert-butyl dicarbonate (59.6 g, 0.27 mol). After 16 h stirring, the layers were separated, the organic layer was washed with 0.3 N HCl and H2O, and concentrated. Crystallization using heptane and drying under house vacuum (h.v.) afforded 74 g of expected product. MS m/z 292 [M+H]+

1. customwas kept at 5-8° C.
2. temperaturecooling
3. stirringAfter 16 h stirring
4. customthe layers were separated
5. washthe organic layer was washed with 0.3 N HCl and H2O
6. concentrationconcentrated
7. customCrystallization
8. customdrying under house vacuum (h.v.)