Dimethyl Sulfoxide → HCID 15125490, compound

Participants

Reaction Steps

To a stirred mixture of 45 parts of 4-[3-bromo-4-[4-(4-methoxyphenyl)-1-piperazinyl]-phenyl]-2,4-dihydro-3H-1,2,4-triazol-3-one and 90 parts of dimethyl sulfoxide were added 15 parts of potassium hydroxide (pulverized). Then there were added 6.2 parts of 2-bromobutane and the whole was stirred for 20 hours at room temperature. The reaction mixture was poured into water. The produce was extracted with trichloromethane. The extract was dried, filtered and evaporated. The residue was purified by column chromatography over silica gel using a mixture of trichloromethane and methanol (99:1 by volume) as eluent. The pure fractions were collected and the eluent was evaporated. The residue was crystallized from a mixture of methylbenzene and hexane (1:2 by volume). The precipitated product was filtered off and recrystallized from 80 parts of methanol. The product was filtered off and dried in vacuo at 60° C., yielding a first fraction of 14.7 parts (29.8%) of 4-[3-bromo-4-[4-(4-methoxyphenyl)-1-piperazinyl]phenyl]-2,4-dihydro-2-(1-methylpropyl)-3H-1,2,4-triazol-3-one; mp. 144.6° C. The less pure fractions were collected and the eluent was evaporated. The residue was further purified by column chromatography (HPLC) over silica gel using a mixture of ethyl acetate and methanol (97:3 by volume) as eluent. The pure fractions were collected and the eluent was evaporated. The residue was crystallized from methanol, yielding a second fraction of 4-[3-bromo-4-[4-(4-methoxyphenyl)-1-piperazinyl]-phenyl]-2,4-dihydro-2-(1-methylpropyl)-3H-1,2,4-triazol-3-one; mp. 144.7° C. (int. 35).

Provenance & Evidence