反应详情

温度

80 °C

To a solution of 4-ethyl-5-(pyridin-2-yl)isoxazole-3-carboxylic acid, sodium salt (22 mg), HOBt (27.8 mg, 0.181 mmol), and diisopropylethylamine (0.070 mL, 0.403 mmol) in acetonitrile (1 mL) was added EDC (45.4 mg, 0.237 mmol) and tert-butyl 1-(4-(N′-hydroxycarbamimidoyl)benzyl)azetidine-3-carboxylate, Int. 1 (30.8 mg, 0.101 mmol). The reaction mixture was stirred at 80° C. for 4 h. and then concentrated under reduced pressure. The residue was diluted with ethyl acetate (3 mL), washed with a saturated aqueous solution of sodium bicarbonate, washed with water (1 mL), washed with brine (1 mL), and dried over anhydrous sodium sulfate. Concentration followed by purification by preparative HPLC [Prep HPLC: Column: PHENOMENEX® S10 30×100 mm; Gradient time: 10 min; Flow rate=40 ml/min; Solvent A=10% MeOH—90% Water—0.1% TFA; Solvent B=90% MeOH—10% water—0.1% TFA; Start % B=20; Final % B=100.] afforded tert-butyl 1-(4-(5-(4-ethyl-5-(pyridin-2-yl)isoxazol-3-yl)-1,2,4-oxadiazol-3-yl)benzyl)azetidine-3-carboxylate.

1. concentrationconcentrated under reduced pressure
2. additionThe residue was diluted with ethyl acetate (3 mL)
3. washwashed with a saturated aqueous solution of sodium bicarbonate
4. washwashed with water (1 mL)
5. washwashed with brine (1 mL)
6. dry with materialdried over anhydrous sodium sulfate
7. concentrationConcentration
8. customfollowed by purification by preparative HPLC [Prep HPLC
9. custom10 min