反应详情

A mixture of methyl 2,3-dihydroxy-4-methoxybenzoate (0.176 mol), 1,2-dibromo-ethane (0.282 mol), K2CO3 (0.444 mol) and CuO (1.4 g) in DMF (1000 ml) was stirred for 6 hours, cooled, filtered and the filtrate was evaporated. Water (300 ml) was added. The mixture was extracted twice with DCM (300 ml). The organic layer was separated, washed with a saturated NaHCO3 solution, dried, filtered and the solvent was evaporated. The residue was triturated in DIPE. The precipitate was filtered off and dried, yielding 32.1 g of methyl 2,3-dihydro-8-methoxy-1,4-benzodioxin-5-carboxylate (intermediate 1, mp. 84° C.).

1. temperaturecooled
2. filtrationfiltered
3. customthe filtrate was evaporated
4. additionWater (300 ml) was added
5. extractionThe mixture was extracted twice with DCM (300 ml)
6. customThe organic layer was separated
7. washwashed with a saturated NaHCO3 solution
8. customdried
9. filtrationfiltered
10. customthe solvent was evaporated
11. customThe residue was triturated in DIPE
12. filtrationThe precipitate was filtered off
13. customdried