Acetic acid, 2-(triphenylphosphoranylidene)-, ethyl ester → HCID 57845336, compound

HRID 734382Notes

Reaction equation

HRID 734382 reaction equation
[F:1][CH:2]1[C:7](=O)[CH2:6][CH2:5][N:4]([C:9]([O:11][CH2:12][C:13]2[CH:18]=[CH:17][C:16]([CH3:19])=[CH:15][CH:14]=2)=[O:10])[CH2:3]1.[C:20]([CH:25]=P(C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)([O:22][CH2:23][CH3:24])=[O:21]>C1(C)C=CC=CC=1>[CH2:23]([O:22][C:20](=[O:21])/[CH:25]=[C:7]1\[CH:2]([F:1])[CH2:3][N:4]([C:9]([O:11][CH2:12][C:13]2[CH:18]=[CH:17][C:16]([CH3:19])=[CH:15][CH:14]=2)=[O:10])[CH2:5][CH2:6]\1)[CH3:24]

Participants

4

Reactant 2

HCID 70670Acetic acid, 2-(triphenylphosphoranylidene)-, ethyl esterHCID 57845351HCID 57845351, compound

Product 1

HCID 57845336HCID 57845336, compoundYield 81.5%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

To a solution of (±)-4-methylbenzyl 3-fluoro-4-oxopiperidine-1-carboxylate (40 g, 150 mmol) in toluene (200 mL) at RT was added (carbethoxymethylene)triphenylphosphorane (63.0 g, 181 mmol) and the reaction mixture stirred for 1 h. The reaction mnixture was concentrated and purified by silica gel chromatography (gradient elution: 10% to 20% EtOAc in hexanes) to give the olefins (±)-4-methylbenzyl (E)-4-(2-ethoxy-2-oxoethylidene)-3-fluoropiperidine-1-carboxylate and (±)-4-methylbenzyl (Z)-4-(2-ethoxy-2-oxoethylidene)-3-fluoropiperidine-1-carboxylate (41.0 g, 78% yield, 3 steps) as a 3:1 E:Z mixture. This mixture was utilized directly in the next step. A small sample of the mixture was separated by silica gel chromatography for characterization purposes.

Workup

  1. concentrationThe reaction mnixture was concentrated
  2. custompurified by silica gel chromatography (gradient elution: 10% to 20% EtOAc in hexanes)

Sources & evidence

ORD record
ord-ea33bccd0c0c407eb710618a20c2c4b7
Source dataset
uspto-grants-2009_09
Patent number
US07592360B2

Reaction notes

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