(4-Chlorophenyl)acetic acid → 2-(4-Chloro-phenyl)-3-cyclopentyl-propionic acid

HRID 966609Notes

Reaction equation

HRID 966609 reaction equation
C([N-]C(C)C)(C)C.[Li+].[Cl:9][C:10]1[CH:15]=[CH:14][C:13]([CH2:16][C:17]([OH:19])=[O:18])=[CH:12][CH:11]=1.I[CH2:21][CH:22]1[CH2:26][CH2:25][CH2:24][CH2:23]1>O1CCCC1.CN1CCCN(C)C1=O.CN1CCCN(C)C1=O>[Cl:9][C:10]1[CH:11]=[CH:12][C:13]([CH:16]([CH2:21][CH:22]2[CH2:26][CH2:25][CH2:24][CH2:23]2)[C:17]([OH:19])=[O:18])=[CH:14][CH:15]=1

Participants

6

Reactant 3

HCID 15880(4-Chlorophenyl)acetic acidHCID 2724682Lithium diisopropylamideHCID 2762531(Iodomethyl)cyclopentane

Product 1

HCID 223152972-(4-Chloro-phenyl)-3-cyclopentyl-propionic acidYield 79.1%

Reagents, catalysts & solvents 2

HCID 816462(1H)-Pyrimidinone, tetrahydro-1,3-dimethyl-SolventHCID 22565281tetrahydrofuran 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinoneSolvent

Conditions

Temperature
-78 °C

Procedure

A solution of freshly prepared lithium diisopropylamide (78.0 mL of a 0.91M stock solution, 70.98 mmol) cooled to −78° C. was treated with (4-chloro-phenyl)-acetic acid (5.76 g, 33.8 mmol) in tetrahydrofuran/1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone (84 mL, 3:1). The resulting solution was stirred at −78° C. for 1 h. Iodomethylcyclopentane (7.45 g, 35.49 mmol) was then added in 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone (2 mL). This solution was stirred at −78° C. for 4 h. The reaction was then warmed to 25° C. and was stirred at 25° C. for 16 h. The reaction mixture was then quenched by the dropwise addition of a saturated aqueous ammonium chloride solution (20 mL). The excess solvent was removed in vacuo. The residue was acidified to pH=1 with a 1N aqueous hydrochloric acid solution. The mixture was then poured into water (150 mL) and extracted with ethyl acetate (3×50 mL). The combined organic layers were dried over sodium sulfate, filtered, and concentrated in vacuo. Flash chromatography (Merck Silica gel 60, 230-400 mesh, 80/20 hexanes/ethyl acetate) afforded 2-(4-chloro-phenyl)-3-cyclopentyl-propionic acid (6.76 g, 79.1%) as a yellow solid: mp 82-84° C.: EI-HRMS m/e calcd for C14H17ClO2 (M+) 252.0917, found 252.0906.

Workup

  1. stirringThis solution was stirred at −78° C. for 4 h
  2. temperatureThe reaction was then warmed to 25° C.
  3. stirringwas stirred at 25° C. for 16 h
  4. customThe reaction mixture was then quenched by the dropwise addition of a saturated aqueous ammonium chloride solution (20 mL)
  5. customThe excess solvent was removed in vacuo
  6. additionThe mixture was then poured into water (150 mL)
  7. extractionextracted with ethyl acetate (3×50 mL)
  8. dry with materialThe combined organic layers were dried over sodium sulfate
  9. filtrationfiltered
  10. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-2bf4527422b84f659e39ff5281c298be
Source dataset
uspto-grants-2005_10
Patent number
US06951945B2

Reaction notes

Loading…