ⓘ Medroxalol

                                     

ⓘ Medroxalol

For the first step, salicylamide 1 is the subject of a Friedel-Crafts acetylation and then the aromatic methylketone is halogenated. in the usual manner. The bromide in 2 is then displaced by the nitrogen in N -benzyl-1-3.4-methylenedioxyphenyl-3-butylamine 3, which is itself prepared by reductive amination on the corresponding ketone. The product of the last step 4 is catalytically hydrogenated. This serves the dual purpose both of reducing the ketone and removing the benzyl protecting group affording the product medroxalol 5. Note that a benzyl protecting group is not necessarily used.