1,2-dimethoxy-6,7,8,9-tetrahydro-5H-benzo[7]annulen-5-one → HCID 19841205, compound

HRID 1638797Notes

Reaction equation

HRID 1638797 reaction equation
[CH3:1][O:2][C:3]1[C:8]2[CH2:9][CH2:10][CH2:11][CH2:12][C:13](=[O:14])[C:7]=2[CH:6]=[CH:5][C:4]=1[O:15][CH3:16].C[O-:18].[Na+].C[O:21][CH3:22].[Na]>CO>[CH3:1][O:2][C:3]1[C:8]2[CH2:9][CH2:10][CH2:11][CH:12]([C:22]([OH:21])=[O:18])[C:13](=[O:14])[C:7]=2[CH:6]=[CH:5][C:4]=1[O:15][CH3:16]

Participants

5

Reactant 3

HCID 3164831,2-dimethoxy-6,7,8,9-tetrahydro-5H-benzo[7]annulen-5-oneHCID 10942334Sodium MethoxideHCID 131716195HCID 131716195, compound

Product 1

HCID 19841205HCID 19841205, compound

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A mixture of 1,2-dimethoxy-6,7,8,9-tetrahydro-5H-benzocyclohepten-5-one [Itoh et al., Chem. Pharm. Bull., 26, 504 (1978)] (2.2 g), powdery sodium methoxide [prepared by subjecting a 28% methanol solution of sodium methyoxide (8.5 g) to evaporation to dryness under reduced pressure] and dimethyl carbonate (40 ml) is heated for 9 hours under reflux in a stream of nitrogen. After cooling and subsequent addition of water (100 ml) and ethyl acetate (200 ml), the mixture is made acid with hydrochloric acid and shaken thoroughly. The organic layer is separated and evaporated under reduced pressure to give methyl ester of 1,2-dimethoxy-5-oxo-6,7,8,9,-tetrahydro-5H-benzocycloheptene-6-carboxylic acid. This product is dissolved in a mixture of methylene chloride (50 ml) and methanol (50 ml). To the solution is added sodium borohydride (0.5 g), and the mixture is stirred for 30 minutes. After addition of water (200 ml), the reaction mixture is extracted with methylene chloride (100 ml). The organic layer is evaporated under reduced pressure. The residue is purified by silica gel column chromatography (hexane:ethyl acetate=2:1) to give methyl ester of 1,2-dimethoxy-5-hydroxy-6,7,8,9-tetrahydro-5H-benzocycloheptene-6-carboxylic acid (1.6 g) as a pale yellow oily product.

Workup

  1. customprepared
  2. customto evaporation to dryness under reduced pressure] and dimethyl carbonate (40 ml)
  3. temperatureis heated for 9 hours
  4. temperatureunder reflux in a stream of nitrogen
  5. temperatureAfter cooling
  6. additionsubsequent addition of water (100 ml) and ethyl acetate (200 ml)
  7. customThe organic layer is separated
  8. customevaporated under reduced pressure

Sources & evidence

ORD record
ord-878592528e33413ebfd4c2564f4df4c2
Source dataset
uspto-grants-1989_11
Patent number
US04880809

Reaction notes

Loading…