Diisopropylamine → 2-(3-Chloro-4-methylsulfanyl-phenyl)-3-(tetrahydro-pyran-4-yl)-propionic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

A solution of diisopropylamine (0.33 mL, 2.38 mmol) in tetrahydrofuran (6 mL) cooled to −78° C. under an argon atmosphere was treated with a 2.5M solution of n-butyllithium in hexanes (0.95 mL, 2.38 mmol). The reaction mixture was stirred at −78° C. for 15 min, after which time, a solution of (3-chloro-4-methylsulfanyl-phenyl)-acetic acid methyl ester (prepared as in Example 4, 500 mg, 2.17 mmol) in tetrahydrofuran (1 mL) and 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone (0.5 mL) was slowly added via a cannula. The greenish yellow solution was allowed to stir at −78° C. for 1 h, after which time, a solution of 4-iodomethyl-tetrahydro-pyran (588 mg, 2.60 mmol) in 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone (0.5 mL) was added via a cannula. The reaction mixture was then allowed to warm to 25° C., where it was stirred for 16 h. The reaction mixture was then quenched by the addition of a saturated aqueous ammonium chloride solution (30 mL). This solution was extracted with ethyl acetate (3×20 mL). The combined organic layers were washed with a 10% aqueous sulfuric acid solution (2×50 mL) and a saturated aqueous sodium bicarbonate solution (2×50 mL), dried over sodium sulfate, filtered, and concentrated in vacuo. Biotage chromatography (FLASH 40S, Silica, 75/25 hexanes/ethyl acetate) afforded 2-(3-chloro-4-methylsulfanyl-phenyl)-3-(tetrahydro-pyran-4-yl)-propionic acid methyl ester (431 mg, 61%) as a yellow oil: EI-HRMS m/e calcd for C16H21ClO3S (M+) 328.0900, found 328.0898.

Provenance & Evidence