Sulfuric Acid → HCID 22397358, compound

Participants

Reaction Steps

A stirred mixture of 4-[1-(4-fluorophenyl)-1H-indazol-3-yl]piperidine-1-carbonitrile of Example 102 (30 g, 0.094 moles) and 25% H2SO4 (225 ml) was refluxed for 20 hours. The mixture was cooled, poured into H2O, and basified with a 25% NaOH solution. The product was extracted (dichloromethane), dried (MgSO4), and concentrated to yield 21 g (76%) of 1-(4-fluorophenyl)-3-(4-piperidinyl)-1H-indazole as an oil. To a stirred suspension of the indazole (5.0 g, 0.017 moles) in toluene (90 ml) was added methyl isocyanate (1.1 ml, 0.019 moles). The mixture was stirred for 16 hours at ambient temperature and then concentrated to yield 5.8 g of an oil. The oil was triturated with ether causing the product to solidify. The product was recrystallized twice from isopropyl alcohol-hexane to yield 3.44 g (58%) of N-methyl-4-[1-(4-fluorophenyl)- 1H-indazol-3-yl]piperidine-1-carboxamide, m.p. 113°-115° C.

Provenance & Evidence