3-Methoxypropyne → 2(R)-(3-chloro-4-methanesulfonyl-phenyl)-3-cyclopentyl-N-[5-(3-methoxy-prop-1-ynyl)-pyrazin-2-yl]-propionamide

Participants

Reaction Conditions

Reaction Steps

A suspension of N-(5-bromo-pyrazin-2-yl)-2(R)-(3-chloro-4-methanesulfonyl-phenyl)-3-cyclopentyl-propionamide (prepared as in Example 6, 486 mg, 1.0 mmol) in toluene (8 mL) was treated with N,N-diisopropylethylamine (2 mL), 3-methoxypropyne (350 mg, 10.0 mmol), dichlorobis(triphenylphosphine)palladium(II) (40 mg), and copper(I) iodide (20 mg). The mixture was stirred at 25° C. overnight, and an oily black precipitate was obtained. The top clear solution was decanted, and the oily precipitate was rinsed with toluene (5 mL). The residue was dissolved in methylene chloride and extracted with methylene chloride and a 0.2N aqueous hydrochloric acid solution. The organic layer was washed with a saturated aqueous sodium chloride solution, dried over sodium sulfate, filtered, and concentrated in vacuo. Flash chromatography (1/3 to 1/2 ethyl acetate/hexane) afforded 2(R)-(3-chloro-4-methanesulfonyl-phenyl)-3-cyclopentyl-N-[5-(3-methoxy-prop-1-ynyl)-pyrazin-2-yl]-propionamide (330 mg, 69.5%) as a fluffy solid: (ES)+-HRMS m/e calcd for C23H26ClN3O4S (M+H)+ 476.1406, found 476.1405.

Provenance & Evidence