2,6-Lutidine → HCID 10075193, compound

Participants

Reaction Conditions

Reaction Steps

A solution of 2(R)-(3-chloro-4-methanesulfonyl-phenyl)-3-(4-oxo-cyclohexyl)-propionic acid (200 mg, 0.56 mmol) and triphenylphosphine (195 mg, 0.73 mmol) in methylene chloride (4.0 mL) cooled to 0° C. was treated with N-bromosuccinimide (128 mg, 0.73 mmol) in small portions. After the complete addition of N-bromosuccinimide, the reaction mixture was allowed to warm to 25° C. over 30 min. The bright orange reaction mixture was then treated with 2-amino-5-bromopyrazine (200 mg, 1.12 mmol, prepared according to Tetrahedron 1988, 44, 2977-2983) and 2,6-lutidine (0.28 mL, 2.24 mmol). The resulting reaction mixture was stirred at 25° C. for 4 h. The reaction mixture was then diluted with methylene chloride (25 mL) and was successively washed with a 10% aqueous hydrochloric acid solution 1×20 mL), a saturated aqueous sodium bicarbonate solution 1×20 mL) and water 1×20 mL), dried over sodium sulfate, filtered, and concentrated in vacuo. Biotage chromatography (FLASH 40S, Silica, 65/35 hexanes/ethyl acetate eluted to 4/6 hexanes/ethyl acetate) afforded N-(5-bromo-pyrazin-2-yl)-2(R)-(3-chloro-4-methanesulfonyl-phenyl)-3-(4-oxo-cyclohexyl)-propionamide (120 mg, 42%) as an off-white foam: [α]23589=−24.6° (c=0.50, chloroform); EI-HRMS m/e calcd for C20H21BrClN3O4S (M+Na)+ 536.0017. found 536.0022.

Provenance & Evidence