Propafenone pharmaceutical intermediate 3- (a-ethyl benzyl) - 4 - hydroxyl coumarin synthesis method

摘要

#$%^&*AU2016102293A420170223.pdf#####ABSTRACT Propafenone pharmaceutical intermediate 3- (a -ethyl benzyl) 4 - hydroxyl coumarin synthesis method , comprising the following steps: the reaction vessel was added 0.21mol 4-hydroxycoumarin (2), 0.26-0.29mol ethylbenzyl amine (3), the solution temperature was increased to 110-115 C, continued the reaction for 3-5h, reducing the solution temperature to 10-15 C, adding 300ml potassium sulfate solution, extracted with acetonitrile solution, the solution was poured into 1.3L oxalic acid solution, precipitated solid was filtered, washed with salt solution, the filter cake was added into 2.3L potassium bromide solution, the solution temperature is raised to 90-95 C, maintained for 2-3h, the temperature of the solution is reduced to 5--9 C, the precipitated solid was washed with cyclohexane solution, dehydrated with dehydrating agent, recrystallized in nitromethane solution , got crystals of 3- (a -ethyl benzyl) - 4 - hydroxyl coumarin .