Acetic acid, 2-(triphenylphosphoranylidene)-, ethyl ester → HCID 367206, compound

HRID 868280Notes

Reaction equation

HRID 868280 reaction equation
[C:1]([CH:6]=P(C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)([O:3][CH2:4][CH3:5])=[O:2].[Br:26][C:27]1[CH:34]=[CH:33][CH:32]=[CH:31][C:28]=1[CH:29]=O>C(Cl)Cl>[Br:26][C:27]1[CH:34]=[CH:33][CH:32]=[CH:31][C:28]=1[CH:29]=[CH:6][C:1]([O:3][CH2:4][CH3:5])=[O:2]

Participants

4

Reactant 2

HCID 70670Acetic acid, 2-(triphenylphosphoranylidene)-, ethyl esterHCID 811292-Bromobenzaldehyde

Product 1

HCID 367206HCID 367206, compoundYield 96%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

Carboethoxymethylidene triphenylphosphorane (94 g, 270 mM) was dissolved in 350 ml of methylenechloride under nitrogen. o-Bromobenzaldehyde (31.5 ml; 270 mM) was added via an addition funnel in 125 ml of methylene chloride. The solution was allowed to stand at room temperature overnight and then the solvent was removed in vacuo. The slushy residue was taken up in 10% ethyl acetate in hexane and filtered through a one-inch pad of silica gel in a 350 ml fritted funnel with one liter of 10% ethyl acetate in hexane. Solvent removal on the rotary evaporator followed by pumping overnight gave 66.3 g of an oil, ethyl o-bromocinnamate in 96% yield. The NMR indicates a 4.5 to 1 mixture of trans to cis isomers. NMR:

Workup

  1. customthe solvent was removed in vacuo
  2. filtrationfiltered through a one-inch pad of silica gel in a 350 ml fritted funnel with one liter of 10% ethyl acetate in hexane
  3. customSolvent removal
  4. customon the rotary evaporator
  5. waitby pumping overnight

Sources & evidence

ORD record
ord-b4af5c146f18476b9e394997a4ef0a63
Source dataset
uspto-grants-1988_10
Patent number
US04778818

Reaction notes

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