Triethyl phosphonoacetate → 5-(2,4-Dichlorophenyl)-4-methylpenta-2,4-dienoic acid ethyl ester

HRID 597889Notes

Reaction equation

HRID 597889 reaction equation
[H-].[Na+].[CH2:3]([O:5][C:6](=[O:16])[CH2:7]P(OCC)(OCC)=O)[CH3:4].[Cl:17][C:18]1[CH:23]=[C:22]([Cl:24])[CH:21]=[CH:20][C:19]=1[CH:25]=[C:26]([CH3:29])[CH:27]=O>C1COCC1>[CH2:3]([O:5][C:6](=[O:16])[CH:7]=[CH:27][C:26]([CH3:29])=[CH:25][C:19]1[CH:20]=[CH:21][C:22]([Cl:24])=[CH:23][C:18]=1[Cl:17])[CH3:4]

Participants

5

Reactant 3

HCID 13345Triethyl phosphonoacetateHCID 24758Sodium hydrideHCID 724731863-(2,4-Dichlorophenyl)-2-methylpropenal

Product 1

HCID 724730035-(2,4-Dichlorophenyl)-4-methylpenta-2,4-dienoic acid ethyl esterYield 89.4%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent3×

Procedure

Sodium hydride (4.88 g of a 60% dispersion in mineral oil, 1.5 eq, 0.122 mol) was suspended in THF (442 mL). To this suspension was added a solution of diethoxyphosphorylactic acid ethyl ester (27.5 g, 0.122 mol, 1.5 eq) in THF (10 mL), dropwise. After 10 minutes a solution of 3-(2,4-dichlorophenyl)-2-methylpropenal (17.56 g, 0.082 mol) in THF (50 mL) was added, dropwise. After stirring for 4 hours the mixture was added to NH4Cl(sat) and extracted with EtOAc. The combined organic extracts were dried (MgSO4), concentrated under reduced pressure to give a residue that was purified by silica gel chromatography (0-2.5-5% EtOAc in hexanes) to give 20.9 g of 5-(2,4-dichlorophenyl)-4-methylpenta-2,4-dienoic acid ethyl ester.

Workup

  1. extractionextracted with EtOAc
  2. dry with materialThe combined organic extracts were dried (MgSO4)
  3. concentrationconcentrated under reduced pressure
  4. customto give a residue that
  5. customwas purified by silica gel chromatography (0-2.5-5% EtOAc in hexanes)

Sources & evidence

ORD record
ord-9376aad7de7a4e8f9b62f2b2018f5d9e
Source dataset
uspto-grants-2011_03
Patent number
US07897601B2

Reaction notes

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