Sodium borohydride → 7-Methoxycarbonyl-1,2,3,4-tetrahydro-1-naphthol

HRID 1779956Notes

Reaction equation

HRID 1779956 reaction equation
[CH3:1][O:2][C:3]([C:5]1[CH:14]=[C:13]2[C:8]([CH2:9][CH2:10][CH2:11][C:12]2=[O:15])=[CH:7][CH:6]=1)=[O:4].[BH4-].[Na+]>CO.O1CCCC1>[CH3:1][O:2][C:3]([C:5]1[CH:14]=[C:13]2[C:8]([CH2:9][CH2:10][CH2:11][CH:12]2[OH:15])=[CH:7][CH:6]=1)=[O:4]

Participants

5

Reactant 2

HCID 4311764Sodium borohydrideHCID 10987358Methyl 8-oxo-5,6,7,8-tetrahydronaphthalene-2-carboxylate

Product 1

HCID 158852487-Methoxycarbonyl-1,2,3,4-tetrahydro-1-naphthol

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 8028TetrahydrofuranSolvent

Conditions

Temperature
5 °C

Procedure

In a mixture of 150 ml of methanol and 50 ml of tetrahydrofuran, 24.1 g of 7-methoxycarbonyl-3,4-dihydro-(2H)-1-naphthalenone was dissolved and 5 g of sodium borohydride was added by portions with ice cooling. The mixture was stirred at 5° C. for an hour and successively the solvent was distilled off under reduced pressure. The concentrated residue was adjusted to pH 2 by adding a 2N aqueous hydrochloric acid solution and extracted with chloroform. The chloroform layer was dried with anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure to obtain crude intermediate 7-methoxycarbonyl-1,2,3,4-tetrahydro-1-naphthol. The crude intermediate was dissolved in 150 ml of benzene, 5 g of Amberlyst 15 was added, a Dean-Stark Trap was mounted, and the mixture was refluxed by heating for 2 hours. After cooling, the reaction mixture was filtered and the solvent was distilled off under reduced pressure. The concentrated residue was purified by silica gel column chromatography using a mixture, ethyl acetate: n-hexane=1:10, as a developer. 7-methoxycarbonyl-3,4-dihydronaphthalene thus obtained was 19.2 g.

Workup

  1. dissolutionwas dissolved
  2. distillationsuccessively the solvent was distilled off under reduced pressure
  3. additionby adding a 2N aqueous hydrochloric acid solution
  4. extractionextracted with chloroform
  5. dry with materialThe chloroform layer was dried with anhydrous magnesium sulfate
  6. distillationThe solvent was distilled off under reduced pressure

Sources & evidence

ORD record
ord-e7d25761abd64108b6b8ed86ce1978b6
Source dataset
uspto-grants-1997_05
Patent number
US05629321

Reaction notes

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