반응 #43297

반응 방정식

2,3-dihydroxy-4-methoxy benzoic acid methyl ester

1,3-dibromopropane

K2CO3

→

intermediate 7

methyl 3,4-dihydro-9-methoxy-2H-1,5-benzodioxepin-6-carboxylate

용매

DMF

반응 조건

후처리

1. 1
   온도cooled
2. 2
   여과filtered
3. 3
   기타The solvent was evaporated
4. 4
   workup.ADDITIONHCl (aqueous solution of 0.5 N, 1000 ml)) was added
5. 5
   추출The mixture was extracted twice with DCM (750 ml)
6. 6
   기타The organic layer was separated
7. 7
   기타dried
8. 8
   여과filtered
9. 9
   기타the solvent was evaporated
10. 10
    기타The residue was purified by column chromatography over silica gel (eluent: hexane/ethyl acetate/DCM 70/30/15)
11. 11
    기타The pure fractions were collected
12. 12
    기타the solvent was evaporated
13. 13
    기타The residue was crystallized from DIPE

실험 절차

A mixture of 2,3-dihydroxy-4-methoxy benzoic acid methyl ester (0.45 mol), 1,3-dibromopropane (0.72 mol), K2CO3 (155 g) and CuO (3.6 g) in DMF (2500 ml) was stirred at 120° C. to 130° C. for 7 hours, cooled and filtered. The solvent was evaporated. HCl (aqueous solution of 0.5 N, 1000 ml)) was added. The mixture was extracted twice with DCM (750 ml). The organic layer was separated, dried, filtered and the solvent was evaporated. The residue was purified by column chromatography over silica gel (eluent: hexane/ethyl acetate/DCM 70/30/15). The pure fractions were collected and the solvent was evaporated. The residue was crystallized from DIPE, yielding methyl 3,4-dihydro-9-methoxy-2H-1,5-benzodioxepin-6-carboxylate (intermediate 7).

출처