Formic Acid → 4-formyl-1-(1-phenyl-1H-indazol-3-yl)piperazine

Participants

Reaction Steps

To a solution of 3.4 ml of acetic anhydride and 1.5 ml of formic acid heated at 55° C. for 1.5 hours and then cooled to ambient temperature was added, dropwise, a solution of 5.6 g of 1-phenyl-3-(1-piperazinyl)-1H-indazole in 20 ml of tetrahydrofuran. The reaction mixture was stirred at ambient temperature for 2 hours and then concentrated to an oil. Trituration of the oil with refluxing diethyl ether yielded a solid which was recrystallized from isopropanol (3×) to yield 2.6 g (42%) of 4-formyl-1-(1-phenyl-1H-indazol-3-yl)piperazine, m.p. 130°-132°.

Provenance & Evidence