Piperidine → Minoxidil

Participants

Reaction Steps

76 g (0.2 mole) of 6-acetamido-1-acetoxy-1,2-dihydro-2-imino-4-(4-toluenesulfonyloxy)pyrimidine are added to 760 ml of anhydrous piperidine at a temperature of 0° to 5° C. while stirring. The mixture is stirred at the same temperature for additional 2 hours, then let to warm to room temperature and stirred for additional 24 hours. The piperidine is distilled off under reduced pressure, 500 ml of water are added to the residue, then the mixture is left to stand in the refrigerator overnight. The precipitate is filtered, washed with water and filtered by strong suction. The filter cake is washed by suspending it 3 times with 50 ml of ether each and dried to give the aimed product in a yield of 23.0 g (55%).

Provenance & Evidence