Phosphorus oxide (P4O10) → 1,1-Dimethyl-1,2,3,4-tetrahydronaphthalene

HRID 1976620Notes

Reaction equation

O=P12OP3(OP(OP(O3)(O1)=O)(=O)O2)=O.O[C:16]([CH3:27])([CH2:18][CH2:19][CH2:20][C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1)[CH3:17]>CS(O)(=O)=O>[CH3:17][C:16]1([CH3:27])[C:26]2[C:21](=[CH:22][CH:23]=[CH:24][CH:25]=2)[CH2:20][CH2:19][CH2:18]1

Participants

Conditions

Temperature: 105 °C

Procedure

A mixture of P2O5 (55.3 g, 0.390 mol) in 400 ml of methanesulfonic acid was heated to 105° C. under argon until all of the solid had dissolved. The resulting solution was cooled to room temperature and 2-hydroxy-2-methyl-5-phenylpentane (63.0 g, 0.354 mol) added slowly with stirring. After 4 hours the reaction was quenched by carefully pouring the solution onto 1 L of ice. The resulting mixture was extracted with Et2O (4×125 ml)and the combined organic layers washed with water, saturated aqueous NaHCO3, water, and saturated aqueous NaCl before being dried over MgSO4. Concentration of the solution under reduced pressure, followed by distillation afforded 51.0 g (90%) of the product as a clear colorless oil, bp. 65-67° C./1.1 mmHg. 1H NMR (CDCl3): δ 7.32 (1H, d, J=7.4 Hz), 7.16-7.05 (3H, m), 2.77 (2H, t, J=6.3 Hz), 1.80 (2H, m), 1.66 (2H, m), 1.28 (6H, s).

Workup

dissolutionhad dissolved
temperatureThe resulting solution was cooled to room temperature
customAfter 4 hours the reaction was quenched
additionby carefully pouring the solution onto 1 L of ice
extractionThe resulting mixture was extracted with Et2O (4×125 ml)
washthe combined organic layers washed with water, saturated aqueous NaHCO3, water, and saturated aqueous NaCl
dry with materialbefore being dried over MgSO4
distillationConcentration of the solution under reduced pressure, followed by distillation

Sources & evidence

ORD record: ord-941c41f0d53f48efb9445cbc83c790d9
Source dataset: uspto-grants-2001_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06228848B1

Reaction notes

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