Acetic Acid → 4,4-Dimethyl-3,4-dihydro-2H-naphthalen-1-one

HRID 613293Notes

Reaction equation

HRID 613293 reaction equation
[C:1]([OH:4])(=O)[CH3:2].C(OC(=O)C)(=O)C.[CH3:12][C:13]1([CH3:23])[C:22]2[C:17](=[CH:18]C=C[CH:21]=2)[CH2:16][CH2:15][CH2:14]1>C1C=CC=CC=1.O>[CH3:12][C:13]1([CH3:23])[C:14]2[C:2](=[CH:18][CH:17]=[CH:16][CH:15]=2)[C:1](=[O:4])[CH2:21][CH2:22]1

Participants

6

Reactant 3

HCID 176Acetic AcidHCID 7918Acetic AnhydrideHCID 161371,1-Dimethyl-1,2,3,4-tetrahydronaphthalene

Product 1

HCID 2365474,4-Dimethyl-3,4-dihydro-2H-naphthalen-1-oneYield 74%

Reagents, catalysts & solvents 2

HCID 241BenzeneSolvent2×HCID 962WaterSolvent

Conditions

Temperature
0 °C

Procedure

A solution of 350 ml of glacial acetic acid and 170 ml of acetic anhydride was cooled to 0° C. and CrO3, 25.0 g (0.25 mol) carefully added in small portions. The resulting mixture was stirred for 30 minutes before 120 ml of benzene was added. 1,2,3,4-tetrahydro-1,1-dimethylnaphthalene was added slowly as a solution in 30 ml of benzene. Upon completing the addition the reaction was stirred for 4 hours at 0° C. The solution was diluted with H2O (200 ml) and extracted with Et2O (5×50 ml). The combined organic layers were washed with water, saturated aqueous NaCO3, and saturated aqueous NaCl, before being dried over MgSO4. Removal of the solvents under reduced pressure, and distillation afforded 16.0 g (74%) of the product as a pale-yellow oil, bp 93-96° C./0.3 mm Hg 1H NMR (CDCl3): δ 8.02 (1H, dd, J=1.3, 7.8 Hz), 7.53 (1H, m ), 7.42 (1H, d, J=7.9 Hz), 7.29 (1H, m), 2.74 (2H, t, J=6.8 Hz), 2.02 (2H, t, J=6.8 Hz), 1.40 (6H, s).

Workup

  1. additionCrO3, 25.0 g (0.25 mol) carefully added in small portions
  2. additionwas added
  3. additionthe addition the reaction
  4. extractionextracted with Et2O (5×50 ml)
  5. washThe combined organic layers were washed with water, saturated aqueous NaCO3, and saturated aqueous NaCl
  6. dry with materialbefore being dried over MgSO4
  7. customRemoval of the solvents
  8. distillationunder reduced pressure, and distillation

Sources & evidence

ORD record
ord-5d7d318fde494f40852d1013bcaf599d
Source dataset
uspto-grants-1999_12
Patent number
US06008204

Reaction notes

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