Hydrochloric Acid → 3-Ethyl-1-methoxy-5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalene-2-carboxaldehyde

HRID 1979895Notes

Reaction equation

[CH2:1]([C:3]1[C:4]([CH:18]=[O:19])=[C:5]([OH:17])[C:6]2[C:7]([CH3:16])([CH3:15])[CH2:8][CH2:9][C:10]([CH3:14])([CH3:13])[C:11]=2[CH:12]=1)[CH3:2].[OH-].[K+].S(OC)(O[CH3:26])(=O)=O.Cl>C1(C)C=CC=CC=1>[CH2:1]([C:3]1[C:4]([CH:18]=[O:19])=[C:5]([O:17][CH3:26])[C:6]2[C:7]([CH3:16])([CH3:15])[CH2:8][CH2:9][C:10]([CH3:14])([CH3:13])[C:11]=2[CH:12]=1)[CH3:2]

Participants

Conditions

Temperature: 45 °C

Procedure

3-Ethyl-1-hydroxy-5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalene-2-carboxaldehyde (48.2 g, 0.185 mol) was stirred with toluene (650 mL), and potassium hydroxide 85% (19.5 g, 0.296 mol) was added in one portion. The mixture was heated to 45° C. and dimethyl sulfate (35 g, 0.278 mol) was added during 0.5 h at 45°-50° C. The heating was continued for an additional 0.5 h at 50° C. The mixture was cooled to 20° C., neutralized with 5% hydrochloric acid, washed with water (50 mL), and then finally washed with brine (30 mL). Solvent was removed by distillation and the residue distilled to give 3-ethyl-1-methoxy-5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalene-2-carboxaldehyde (40.6 g), GLC purity 98%. Crystallization from hexane gave 27 g of material, GLC purity 99%, exhibiting the expected spectral data.

Workup

additionwas added in one portion
temperatureThe mixture was cooled to 20° C.
washwashed with water (50 mL)
washfinally washed with brine (30 mL)
customSolvent was removed by distillation
distillationthe residue distilled

Sources & evidence

ORD record: ord-b2575f34f1fe4a31b037312cfa87d5fc
Source dataset: uspto-grants-1984_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04483786

Reaction notes

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