Hydrogen Bromide → Itraconazole Hydroxy Isopropyltriazolone Impurity

Participants

Reaction Steps

A mixture of 4.7 parts of 2,4-dihydro-4-[4-[4-(4-methoxyphenyl)-1-piperazinyl]phenyl]-2-(1-methylethyl)-3H-1,2,4-triazol-3-one and 75 parts of a hydrobromic acid solution 48% in water was stirred and refluxed for 3 hours. The reaction mixture was evaporated and the residue was dissolved in a mixture of methanol and water. The whole was neutralized with a sodium hydrogen carbonate solution and the product was extracted with trichloromethane. The extract was dried, filtered and evaporated. The residue was triturated in 2-propanol, yielding 3.9 parts (86%) of 2,4-dihydro-4-[4-[4-(4-hydroxyphenyl)-1-piperazinyl]phenyl]-2-(1-methylethyl)-3H-1,2,4-triazol-3-one, mp. 208.4° C. (intermediate 10).

Provenance & Evidence