Sodium Hydroxide → 5,8-Dimethoxy-3,4-dihydronaphthalene-2-carboxylic acid

HRID 2057732Notes

Reaction equation

HRID 2057732 reaction equation
[CH3:1][O:2][C:3]1[CH:12]=[CH:11][C:10]([O:13][CH3:14])=[C:9]2[C:4]=1[CH2:5][CH2:6][C:7]([C:15]([O:17]CC)=[O:16])=[CH:8]2.[OH-].[Na+]>C(O)C>[CH3:1][O:2][C:3]1[CH:12]=[CH:11][C:10]([O:13][CH3:14])=[C:9]2[C:4]=1[CH2:5][CH2:6][C:7]([C:15]([OH:17])=[O:16])=[CH:8]2

Participants

4

Reactant 2

HCID 14798Sodium HydroxideHCID 20330113HCID 20330113, compound

Product 1

HCID 124335385,8-Dimethoxy-3,4-dihydronaphthalene-2-carboxylic acid

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

Ethyl 3,4-dihydro-5,8-dimethoxy-2-naphthoate (7.50 g, 28.6 mmole) is added to a mixture of ethanol (50 ml) and a 2 N aqueous solution of sodium hydroxide (25 ml), and the resultant mixture is boiled for 5 hours. After completion of the reaction, the reaction mixture is concentrated to the one-fourth of the amount, diluted with water (50 ml) and washed with ether (100 ml×2). The aqueous layer is made acidic with conc. hydrochloric acid, and the precipitated white solid is collected by filtration and then dried (6.50 g, 97%). M.P.<220° C. Recrystallization from ethanol affords an analytical sample of 9b as colorless needles. M.P.<220° C. IRνmaxNujol cm-1 : 1660 (COOH), NMR (in CDCl3 - DMSO-d6): 2.20-3.00 (4H, m, CH2CH2C=), 3.80 (3H, s, OCH3), 3.82 (3H, s, OCH3), 6.75 (1H, d, J=10.7Hz, one of aromatic protons), 6.93 (1H, d, J=10.7Hz, one of aromatic protons), 7.82 (1H, broad s, CH=).

Workup

  1. customAfter completion of the reaction
  2. concentrationthe reaction mixture is concentrated to the one-fourth of the amount
  3. additiondiluted with water (50 ml)
  4. washwashed with ether (100 ml×2)
  5. filtrationthe precipitated white solid is collected by filtration
  6. customdried (6.50 g, 97%)
  7. customRecrystallization from ethanol

Sources & evidence

ORD record
ord-8da504c12db6400895cec9cc7c6a6407
Source dataset
uspto-grants-1980_07
Patent number
US04212828

Reaction notes

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