Phenylacetic Acid → 7-Ethyl-3-phenyl-4H-1-benzopyran-4-one

HRID 2220825Notes

Reaction equation

HRID 2220825 reaction equation
[C:1]1([CH2:7][C:8]([OH:10])=O)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.[CH2:11]([C:13]1[CH:14]=[C:15](O)[CH:16]=[CH:17][CH:18]=1)[CH3:12].N1CC[O:23][CH2:22]C1>[B].CO>[CH2:11]([C:13]1[CH:14]=[C:15]2[C:16]([C:22](=[O:23])[C:7]([C:1]3[CH:2]=[CH:3][CH:4]=[CH:5][CH:6]=3)=[CH:8][O:10]2)=[CH:17][CH:18]=1)[CH3:12]

Participants

6

Reactant 3

HCID 999Phenylacetic AcidHCID 8083MorpholineHCID 121013-Ethylphenol

Product 1

HCID 691435627-Ethyl-3-phenyl-4H-1-benzopyran-4-oneYield 12.2%

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 5462311BoronSolvent

Conditions

Temperature
80 °C

Procedure

This compound was prepared by the same method described for the synthesis of analog 23. To a solution of 6.51 g of phenylacetic acid (47.81 mmol) in 50 ml of boron trifluroide diethyl etherate was added 6.5 ml of 3-ethylphenol (53.20 mmol). The mixture was stirred at 80° C. for 21 hours, cooled to RT, and then washed with aqueous K2CO3 and water until the pH of wash approached neutrality. The product was extracted with ethyl acetate and concentrated. Residue was dissolved in 50 ml of 2-propanol and 8 ml of triethyl formate (48.1 mmol) and 3 ml of morpho line were added. The mixture was stirred at 80° C. for 7 hours and solvent was removed by flash evaporation. The syrup obtained was dissolved in 30 ml of methanol, stirred at 50° C. for 30 min, cooled to room temperature, and kept at 4° C. overnight. Crystals were collected by filtration and washed with small portions of acetone to give 790 mg of analog 35, a yield of 12.2% (based on 3-ethylphenol, w/w): mp 103-104° C. 1H NMR (DMSO-d6) δ 1.35 (t, 3H, —CH3), 2.78 (q, 2H, —CH2—), 7.38 (m, 4′-H), 7.39 (dd, 1H, J=8.10, 1.91 Hz, 6-H), 7.44 (t, 2H, J=7.77 Hz, 3′, 5′-H), 7.52 (d, 1H, J=2.0 Hz, 8H), 7.59 (dd, 2H, J=7.35, 1.38 Hz, 2′, 6′-H), 8.05 (d, 1H, J=8.54 Hz, 5-H), 8.51 (s, 1H, 2-H). 13C NMR (DMSO-d6) δ 14.9 (—CH3), 28.2 (CH2—), 116.7 (C-6, 8), 121.8 (C-10), 123.8 (C-3), 125.4 (C-1′), 125.8 (C-7), 127.8 (C-5), 128.1 (C-3′, 5′), 128.9 (C-2′, 6′), 131.9 (C-4′), 154.4 (C-2), 155.9 (C-9), 174.9 (C-4). MS (m/z), 251.4 (M+H)+, 273.2 (M+Na)+, 249.3 (M−H)−. Anal. (C17H14O2) for C, H. Cacld: 81.58, 6.91; found: 80.92, 6.87.

Workup

  1. customThis compound was prepared by the same method
  2. customdescribed for the synthesis of analog 23
  3. temperaturecooled to RT
  4. washwashed with aqueous K2CO3 and water until the pH
  5. washof wash
  6. extractionThe product was extracted with ethyl acetate
  7. concentrationconcentrated
  8. dissolutionResidue was dissolved in 50 ml of 2-propanol
  9. stirringThe mixture was stirred at 80° C. for 7 hours
  10. customsolvent was removed by flash evaporation
  11. customThe syrup obtained
  12. stirringstirred at 50° C. for 30 min
  13. temperaturecooled to room temperature
  14. waitkept at 4° C. overnight
  15. filtrationCrystals were collected by filtration
  16. washwashed with small portions of acetone
  17. customto give 790 mg of analog 35

Sources & evidence

ORD record
ord-19efb66387024f17bc7133a95b360ae2
Source dataset
uspto-grants-2008_05
Patent number
US07368434B2

Reaction notes

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