preparation | 4-(4-amino-3-fluorophenoxy) pyridine-2-carboxylic acid methylamine can be prepared by a one-step reaction from 4-amino-3-fluorophenol and 4-chloro-n-methylpyridine-2-carboxamide as starting materials. 4-amino-3-fluorophenol (1.27g,10mmol,1.0eq) was added to dried DMF(20ml) and stirred well. Potassium tert-butoxide (1.34g,12mmol,1.0eq) was added and stirred under nitrogen at room temperature for 1H. 4-chloro-n-methylpyridine-2-carboxamide (1.70g,10mmol,1.0eq), heating to 85 deg C to continue the reaction for 10 hours. The reaction solution was quenched with water (100mL), and then extracted with dichloromethane (200mL * 2). The organic phase was dried over anhydrous magnesium sulfate, and the organic phase was spin-dried to obtain an oily liquid, column chromatography (petroleum ether: ethyl acetate = 4:1) was performed to obtain 4-(4-amino-3-fluorophenoxy) pyridine-2-carboxylic acid methylamine (1.3g). |