تفاعل #43297

معادلة التفاعل

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

المذيبات

DMF

ظروف التفاعل

المعالجة

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

الإجراء التجريبي

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).

المصدر