反応 #43297

反応方程式

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

溶媒

DMF

反応条件

後処理

1. 1
   温度cooled
2. 2
   ろ過filtered
3. 3
   その他The solvent was evaporated
4. 4
   workup.ADDITIONHCl (aqueous solution of 0.5 N, 1000 ml)) was added
5. 5
   抽出The mixture was extracted twice with DCM (750 ml)
6. 6
   その他The organic layer was separated
7. 7
   その他dried
8. 8
   ろ過filtered
9. 9
   その他the solvent was evaporated
10. 10
    その他The residue was purified by column chromatography over silica gel (eluent: hexane/ethyl acetate/DCM 70/30/15)
11. 11
    その他The pure fractions were collected
12. 12
    その他the solvent was evaporated
13. 13
    その他The residue was crystallized from DIPE

実験手順

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).

出典