1-Hydroxybenzotriazole → Tert-butyl 1-(4-(5-(4-propyl-3-(pyridin-2-yl)isoxazol-5-yl)-1,2,4-oxadiazol-3-yl)benzyl)azetidine-3-carboxylate

Participants

Reaction Steps

A mixture of 4-propyl-3-(pyridin-2-yl)isoxazole-5-carboxylic acid, lithium salt (13.5 mg, 0.058 mmol), tert-butyl 1-(4-(N′-hydroxycarbamimidoyl)benzyl)azetidine-3-carboxylate, Int. 1 (7.8 mg, 0.058 mmol), HOBt (16.02 mg, 0.105 mmol), N1-((ethylimino)methylene)-N3,N3-dimethylpropane-1,3-diamine hydrochloride (26.1 mg, 0.136 mmol), and diisopropylethylamine (0.041 mL, 0.233 mmol) in acetonitrile (1 mL) was stirred at 80° C. for 2 h. The reaction mixture was concentrated, and the residue was diluted with ethyl acetate (3 mL), washed a saturated aqueous solution of sodium bicarbonate (1 mL), washed with water (1 mL), washed with brine (1 mL), and dried over anhydrous sodium sulfate. Concentration followed by purification by preparative HPLC afforded tert-butyl 1-(4-(5-(4-propyl-3-(pyridin-2-yl)isoxazol-5-yl)-1,2,4-oxadiazol-3-yl)benzyl)azetidine-3-carboxylate.

Provenance & Evidence