Bromo[(4-nitrophenyl)methyl]triphenylphosphine → (trans)-1,2-Dichloro-4-[4-(4-nitrophenyl)-1,3-butadienyl]benzene

HRID 488504Notes

Reaction equation

HRID 488504 reaction equation
BrP([CH2:21][C:22]1[CH:27]=[CH:26][C:25]([N+:28]([O-:30])=[O:29])=[CH:24][CH:23]=1)(C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.C([Li])CCC.[Cl:36][C:37]1[CH:38]=[C:39](/[CH:44]=[CH:45]/[CH:46]=O)[CH:40]=[CH:41][C:42]=1[Cl:43]>C1COCC1>[Cl:43][C:42]1[CH:41]=[CH:40][C:39](/[CH:44]=[CH:45]/[CH:46]=[CH:21][C:22]2[CH:23]=[CH:24][C:25]([N+:28]([O-:30])=[O:29])=[CH:26][CH:27]=2)=[CH:38][C:37]=1[Cl:36]

Participants

5

Reactant 3

HCID 12228628Bromo[(4-nitrophenyl)methyl]triphenylphosphineHCID 13186065(2E)-3-(3,4-dichlorophenyl)prop-2-enalHCID 178418339Butyllithium

Product 1

HCID 86594892(trans)-1,2-Dichloro-4-[4-(4-nitrophenyl)-1,3-butadienyl]benzeneYield 28%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

A mixture of 4-nitro-benzyl bromide (200.0 g, 0.93 mol) and triphenylphosphine (244.0 g, 0.93 mol) in CHCl3 (1.5 L) was heated to reflux for overnight. The reaction mixture was cooled to room temperature, concentrated in vacuo to remove CHCl3 and then suspended in Et2O and stirred rigorously. The suspension was filtered, and the off-white solid was washed with Et2O, dried at 80° C. for 16 hours to give 433.0 g (0.91 mol, 98%) of bromo[(4-nitrophenyl)methyl]triphenylphosphine. A solution of bromo[(4-nitrophenyl)methyl]triphenylphosphine (100.0 g, 0.23 mol) in dry THF (500 mL) was cooled to 5° C. n-Butyl lithium (n-BuLi) (2.4 M, 96 mL, 0.23 mol) was added dropwise to maintain the temperature between 5° C. to 10° C. The cooling bath was then removed, and the reaction mixture was allowed to warm to room temperature. After 4 hours, a solution of (trans)-3-(3,4-dichlorophenyl)-2-propenal (36.2 g, 0.18 mol) in THF (100 mL) was added dropwise, and the resulting mixture was stirred at room temperature for 16 hours. The mixture was filtered, and the filtrate was concentrated in vacuo to give a residue. Purification by flash chromatography (silica gel, 20% EtOAc/hexane) yielded 16.0 g (0.05 mol, 28%) of the desired product. mp 125-135° C.

Workup

  1. additionwas added dropwise
  2. temperatureto maintain the temperature between 5° C. to 10° C
  3. customThe cooling bath was then removed
  4. filtrationThe mixture was filtered
  5. concentrationthe filtrate was concentrated in vacuo
  6. customto give a residue
  7. customPurification by flash chromatography (silica gel, 20% EtOAc/hexane)

Sources & evidence

ORD record
ord-81a97f3c7e6443b48757336a46b9f8ef
Source dataset
uspto-grants-2005_12
Patent number
US06972287B1

Reaction notes

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