Methyl 2-(3,4-dichlorophenyl)acetate → 2-(3,4-Dichloro-phenyl)-3-[3-(tetrahydro-pyran-2-yloxy)-cyclopentyl]-propionic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

A solution of freshly prepared lithium diisopropylamide (23 mL of a 0.31M stock solution, 7.13 mmol) cooled to −78° C. was treated with (3,4-dichloro-phenyl)-acetic acid methyl ester (prepared as in Example 1, 1.42 g, 6.48 mmol) in tetrahydrofuran/1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone (16.15 mL, 3:1). The resulting solution was stirred at −78° C. for 45 min. A solution of 2-(3-iodomethyl-cyclopentyloxy)-tetrahydropyran (2.21 g, 7.13 mmol) in 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone (1 mL) was then added. The reaction mixture was stirred at −78° C. for 2 h. The reaction was then warmed to 25° C. and was stirred at 25° C. for 18 h. The reaction mixture was then quenched by the dropwise addition of a saturated aqueous ammonium chloride solution (10 mL). This mixture was poured into water (100 mL) and extracted with methylene chloride 3×50 mL). The organics were washed with a saturated aqueous lithium chloride solution (1×100 mL), dried over sodium sulfate, filtered, and concentrated in vacuo. Flash chromatography (Merck Silica gel 60, 230-400 mesh, 70/30 hexanes/ethyl acetate) afforded 2-(3,4-dichloro-phenyl)-3-[3-(tetrahydro-pyran-2-yloxy)-cyclopentyl]-propionic acid methyl ester (2.12 g, 81.6%) as a clear oil: EI-HRMS m/e calcd for C20H26Cl2O4 (M+Na)+ 423.1106. found 423.1093.

Provenance & Evidence