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

HRID 364768Notes

Reaction equation

HRID 364768 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

6

Reactant 4

HCID 313Hydrochloric AcidHCID 6497Dimethyl SulfateHCID 14797Potassium HydroxideHCID 190951833-Ethyl-1-hydroxy-5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalene-2-carboxaldehyde

Product 1

HCID 190951923-Ethyl-1-methoxy-5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalene-2-carboxaldehydeYield 80%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Conditions

Temperature
45 °C

Procedure

Methylation. 3-Ethyl-2-formyl-1-hydroxy-5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalene (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-2-formyl-1-methoxy-5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalene (40.6 g), GLC purity 98%. Crystallization from hexane gave 27 g material, GLC purity 99%. 1H-NMR (CDCl3) δ10.38 (1H, s), 6.97 (1H, s), 3.85 (3H, s), 2.89 (2H, q), 1.64 (4H, s), 1.40 (6H, s), 1.28 (6H, s), 1.20 (3H, t). 13C-NMR (CDCl3) δ192.0 (1C, d), 165.3 (1C, s), 153.6 (1C, s), 144.4 (1C, s), 135.7 (1C, s), 125.3 (1C, s), 124.1 (1C, d), 66.0 (1C, q), 38.1 (1C, t), 35.4 (1C, s), 34.8 (1C, t), 34.3 (1C, s), 31.8 (2C, q), 29.8 (2C, q), 26.6 (1C, t), 15.7 (1C, q). IR (KBr) 1275, 1263 cm-1, MS (M/e) 274.2 (M+, 17.1), 258.1 (100.0), 260.3 (20.3), 128.1 (15.1).

Workup

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

Sources & evidence

ORD record
ord-23471de4b39746cba48f178edc6137a8
Source dataset
uspto-grants-1986_08
Patent number
US04605778

Reaction notes

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