Phosphorane, ethylidenetriphenyl- → Ethyl alpha-(3,4-dimethoxyphenyl)crotonate

HRID 616652

Reaction equation

HRID 616652 reaction equation
[CH:1](=P(C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)[CH3:2].[CH3:22][O:23][C:24]1[CH:25]=[C:26]([C:32](=O)[C:33]([O:35][CH2:36][CH3:37])=[O:34])[CH:27]=[CH:28][C:29]=1[O:30][CH3:31]>[Br-].C([P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)C.CCOCC>[CH3:22][O:23][C:24]1[CH:25]=[C:26](/[C:32](=[CH:1]\[CH3:2])/[C:33]([O:35][CH2:36][CH3:37])=[O:34])[CH:27]=[CH:28][C:29]=1[O:30][CH3:31]

Participants

5

Reactant 2

HCID 137195Phosphorane, ethylidenetriphenyl-HCID 170290Benzeneacetic acid, 3,4-dimethoxy-alpha-oxo-, ethyl ester

Product 1

HCID 70615010Ethyl alpha-(3,4-dimethoxyphenyl)crotonate

Reagents, catalysts & solvents 2

HCID 73727Phosphonium, ethyltriphenyl-, bromide (1:1)CatalystHCID 3283Diethyl EtherSolvent2×

Procedure

To a diethyl ether solution of ethylidenetriphenylphosphorane prepared in the usual way from 800 g. of ethyltriphenylphosphonium bromide, 400 g. of ethyl 3,4-dimethoxyphenylglyoxylate in 600 ml. of ether are added dropwise. After refluxing for 4-5 hours, the solvent is evaporated and substituted with tetrahydrofuran. The mixture is then heated for 36 hours and then evaporated to dryness and the residue is extracted with diethyl ether in a Soxhlet apparatus giving 150 g. of the title compound. Pursuant to this procedure, the following other α-arylcrotonate starting materials are prepared:

Workup

  1. temperatureAfter refluxing for 4-5 hours
  2. customthe solvent is evaporated
  3. temperatureThe mixture is then heated for 36 hours
  4. customevaporated to dryness
  5. extractionthe residue is extracted with diethyl ether in a Soxhlet apparatus
  6. customgiving 150 g

Sources & evidence

ORD record
ord-a5755b4f3c46421b8a14187d27c854ba
Source dataset
uspto-grants-1978_02
Patent number
US04075241

Linked notes

Loading…