Benzene → HCID 14347254, compound

HRID 2232756Notes

Reaction equation

HRID 2232756 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]([C:11]([C:15]2[CH:20]=[CH:19][C:18]([O:21][CH3:22])=[C:17]([O:23][CH3:24])[CH:16]=2)=[CH:12]C=O)[CH:6]=[CH:7][C:8]=1[O:9][CH3:10].[C:25]([CH:29]=P(C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)([O:27]C)=[O:26].[CH:49]1C=CC=CC=1>>[CH3:1][O:2][C:3]1[CH:4]=[C:5]([C:11]([C:15]2[CH:20]=[CH:19][C:18]([O:21][CH3:22])=[C:17]([O:23][CH3:24])[CH:16]=2)=[CH:12]/[CH:49]=[CH:29]/[C:25]([OH:27])=[O:26])[CH:6]=[CH:7][C:8]=1[O:9][CH3:10]

Participants

4

Reactant 3

HCID 241BenzeneHCID 17453Acetic acid, 2-(triphenylphosphoranylidene)-, methyl esterHCID 14347231HCID 14347231, compound

Product 1

HCID 14347254HCID 14347254, compound

Conditions

Temperature
55 °C

Procedure

A mixture of 3,3-bis(3,4-dimethoxyphenyl)-2-propenal (19.6 g) and (carbomethoxymethylene)triphenylphosphorane (22 g) in benzene (150 mL) was stirred overnight at 55° C. The solvent was removed under reduced pressure and the residue (45 g), consisting of mainly triphenylphosphine oxide and (E)-5,5-bis(3,4-dimethoxyphenyl)-2,4-pentadienoic acid methyl ester, was taken up a mixture of methanol (100 mL) and 2N sodium hydroxide solution (50 mL) and heated at reflux for 30 minutes. After the methanol was removed in vacuo, the concentrate was diluted water (100 mL) and the precipitated triphenylphosphine oxide was filtered off. The basic filtrate was first extracted with ether to remove neutral impurities. then was poured into 1N hydrochloric acid (300 mL) and extracted with dichloromethane (3×150 mL). The dried (MgSO4) extracts were evaporated and the residue triturated with ether to give 18.7 g of (E)-5,5-bis(3,4-dimethoxyphenyl)-2,4-pentadienoic acid mp 174°-175.5° C. Crystallization from dichloromethane-2-propanol furnished the analytical sample, mp 174°-175.5° C.

Workup

  1. customThe solvent was removed under reduced pressure
  2. additiona mixture of methanol (100 mL) and 2N sodium hydroxide solution (50 mL)
  3. temperatureheated
  4. temperatureat reflux for 30 minutes
  5. customAfter the methanol was removed in vacuo
  6. filtrationthe precipitated triphenylphosphine oxide was filtered off
  7. extractionThe basic filtrate was first extracted with ether
  8. customto remove neutral impurities
  9. additionthen was poured into 1N hydrochloric acid (300 mL)
  10. extractionextracted with dichloromethane (3×150 mL)
  11. dry with materialThe dried (MgSO4) extracts
  12. customwere evaporated
  13. customthe residue triturated with ether

Sources & evidence

ORD record
ord-dd9a4b3b1015415d9036623138d3f8d1
Source dataset
uspto-grants-1988_11
Patent number
US04788206

Reaction notes

Loading…