Hydrochloric Acid → 1,4-Dihydro-1-phenylindeno[1,2-c]pyrazole

Participants

Reaction Steps

2-Hydroxymethlene indan-1-one (Example 1(ii)(a) (6.0 g, 37.5 mmol), phenylhydrazine hydrochloride (Aldrich) (5.48 g, 37.9 mmol), 10 M hydrochloric acid (1 cm3) and ethanol (30 cm3) were stirred under reflux for 19 hours. After cooling, the solvent was evaporated under reduced pressure and the residue dissolved in dichloromethane, then washed with 2M sodium hydroxide. The organic layer was separated, dried (Na2SO4) filtered and concentrated in vacuo. Purification by Kugelrohr distillation afforded an off-white solid (150° C., 0.01 mmHg) m.p. 119-120° C.

Provenance & Evidence