Phosphorus oxide (P4O10) → 2-Methoxy-6,7,8,9-tetrahydro-benzocyclohepten-5-one

HRID 1976114Notes

Reaction equation

HRID 1976114 reaction equation
O=P12OP3(OP(OP(O3)(O1)=O)(=O)O2)=O.[P].[CH3:16][O:17][C:18]1[CH:19]=[C:20]([CH2:24][CH2:25][CH2:26][CH2:27][C:28]([OH:30])=O)[CH:21]=[CH:22][CH:23]=1>>[CH3:16][O:17][C:18]1[CH:23]=[CH:22][C:21]2[C:28](=[O:30])[CH2:27][CH2:26][CH2:25][CH2:24][C:20]=2[CH:19]=1

Participants

4

Reactant 3

HCID 14812Phosphorus oxide (P4O10)HCID 5462309PhosphorusHCID 105844855-(3-methoxyphenyl)pentanoic Acid

Product 1

HCID 2668152-Methoxy-6,7,8,9-tetrahydro-benzocyclohepten-5-oneYield 95%

Conditions

Temperature
100 °C

Procedure

To a homogeneous mixture of phosphorus pentoxide and 85% phosphorus acid at 100° C., was added 5-(3-methoxyphenyl)pentanoic acid in small portions over 20 minutes. The vigorously stirred mixture was heated at 100° C. for 6 hours. Then it was poured on ice-water, and extracted with ether (3 times). The organic phase was washed with water and dried over anhydrous sodium sulfate. Evaporation of the combined organic phase afforded a light yellow oil in more than 95% yield; 1H NMR δ 7.77 (d, 1H, J=8.6 Hz), 6.80 (dd, 1H, J=2.5, 8.6 Hz), 6.69 (d, 1H, J=2.5 Hz), 3.84 (s, 3H), 2.90 (t, 2H, J=6.2 Hz), 2.71 (t, 2H, J=5.9 Hz), 1.91-1.76 (m, 4H).

Workup

  1. additionThen it was poured on ice-water
  2. extractionextracted with ether (3 times)
  3. washThe organic phase was washed with water
  4. dry with materialdried over anhydrous sodium sulfate
  5. customEvaporation of the combined organic phase
  6. customafforded a light yellow oil in more than 95% yield

Sources & evidence

ORD record
ord-48bfbc71dac8467fb59c7c5b1d9f2f50
Source dataset
uspto-grants-2001_05
Patent number
US06225330B1

Reaction notes

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