Dimethyl Sulfoxide → 1-(3-Isopropyl-1,2,4-oxadiazol-5-YL)piperidin-4-one

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A solution of dimethylsulfoxide (1.07 g, 13.7 mmol) in anhydrous dichloromethane (30 mL) was added dropwise over 10 min to oxalyl chloride (2M in dichloromethane; 5.44 mL, 10.9 mmol) which had been cooled to −60° C. The reaction mixture was stirred at −60° C. for 20 min, and then a solution of crude 1-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-4-ol (from Step 2; 2.00 g, ˜9.5 mmol) in anhydrous dichloromethane (100 mL) was added dropwise over 20 min. The reaction mixture was stirred at −60° C. for 1 h, and then triethylamine (2.68 g, 26.5 mmol) was added. The reaction mixture was stirred at −60° C. for 30 min, then allowed to warm to room temperature and stir for 1 h. Dichloromethane (200 mL) was added, and then the mixture was washed with water (3×150 mL) and brine (150 mL). The organic layer was dried (sodium sulfate), filtered, evaporated, and dried under high vacuum to give 1-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-4-one (1.75 g, 88%) as a light tan solid. Mass spectrum (ES) MH+=209.9.

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