1,3-Dibromopropane → HCID 57438494, compound

HRID 1993757Notes

Reaction equation

HRID 1993757 reaction equation
[CH3:1][O:2][C:3](=[O:14])[C:4]1[CH:9]=[CH:8][C:7]([O:10][CH3:11])=[C:6]([OH:12])[C:5]=1[OH:13].Br[CH2:16][CH2:17][CH2:18]Br.C([O-])([O-])=O.[K+].[K+]>CN(C=O)C>[CH3:11][O:10][C:7]1[C:6]2[O:12][CH2:16][CH2:17][CH2:18][O:13][C:5]=2[C:4]([C:3]([O:2][CH3:1])=[O:14])=[CH:9][CH:8]=1

Participants

5

Reactant 3

HCID 80011,3-DibromopropaneHCID 11430Potassium CarbonateHCID 11694090Methyl 2,3-dihydroxy-4-methoxybenzoate

Product 1

HCID 57438494HCID 57438494, compound

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

A mixture of 2,3-dihydroxy4-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).

Workup

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

Sources & evidence

ORD record
ord-e407e845405f4dfb875944c63ed2a301
Source dataset
uspto-grants-2010_01
Patent number
US07652040B2

Reaction notes

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