Acetic acid, 2-(triphenylphosphoranylidene)-, ethyl ester → (E)-5,5-bis(4-fluorophenyl)-2,4-pentadienoic acid ethyl ester

HRID 2232750Notes

Reaction equation

HRID 2232750 reaction equation
[F:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]([C:12]2[CH:17]=[CH:16][C:15]([F:18])=[CH:14][CH:13]=2)=[CH:9][CH:10]=O)=[CH:4][CH:3]=1.[C:19]([CH:24]=P(C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)([O:21][CH2:22][CH3:23])=[O:20]>C(O)C>[CH2:22]([O:21][C:19](=[O:20])/[CH:24]=[CH:10]\[CH:9]=[C:8]([C:12]1[CH:17]=[CH:16][C:15]([F:18])=[CH:14][CH:13]=1)[C:5]1[CH:6]=[CH:7][C:2]([F:1])=[CH:3][CH:4]=1)[CH3:23].[CH2:22]([O:21][C:19](=[O:20])/[CH:24]=[CH:10]/[CH:9]=[C:8]([C:12]1[CH:17]=[CH:16][C:15]([F:18])=[CH:14][CH:13]=1)[C:5]1[CH:6]=[CH:7][C:2]([F:1])=[CH:3][CH:4]=1)[CH3:23]

Participants

5

Reactant 2

HCID 70670Acetic acid, 2-(triphenylphosphoranylidene)-, ethyl esterHCID 108901313,3-Bis(4-fluorophenyl)-2-propenal

Product 2

HCID 14347252(E)-5,5-bis(4-fluorophenyl)-2,4-pentadienoic acid ethyl esterHCID 86742564(Z)-5,5-bis(4-fluorophenyl)-2,4-pentadienoic acid ethyl ester

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

As described in Example 99, 3,3-bis(4-fluorophenyl)-2-propenal (9.8 g) was reacted with (carbethoxymethylene)triphenylphosphorane (14.3 g) in ethanol (20 mL) for 30 minutes at ambient temperature. The mixture of esters obtained from the usual work up was purified by HPLC (dichloromethane-hexane; 1:1) to give 2.0 g of the less polar (Z)-5,5-bis (4-fluorophenyl)-2,4-pentadienoic acid ethyl ester as an oil, and 9.3 g of (E)-5,5-bis(4-fluorophenyl)-2,4-pentadienoic acid ethyl ester. A sample of the (E)-isomer was crystallized from hexane to give the pure ester, mp 71°-72.5° C.

Workup

  1. customobtained from the usual work
  2. customup was purified by HPLC (dichloromethane-hexane; 1:1)

Sources & evidence

ORD record
ord-352898e790604d078b82f830da468466
Source dataset
uspto-grants-1988_11
Patent number
US04788206

Reaction notes

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