Sulfuric Acid → HCID 23048179, compound

Participants

Reaction Steps

A stirred mixture of 4-[1-[4-(trifluoromethyl)phenyl]-1H-indazol-3-yl]piperidine-1-carbonitrile of Example 101 (15 g. 0.041 moles) and 25% H2SO4 (100 ml) was refluxed for 20 hours. The mixture was cooled, poured into H2O, and basified with 25% NaOH solution. The product was extracted (dichloromethane), dried (MgSO4), and concentrated to yield 13 g (93%) of 1-[4-(trifluoromethyl)phenyl]-3-(4-piperidinyl)-1H-indazole as an oil. To a stirred mixture of the indazole (4.15 g. 0.012 moles) and triethylamine (3.35 ml. 0.024 moles) in toluene (50 ml) was added acetyl chloride (0.93 ml, 0.013 moles). The reaction was stirred at ambient temperature for 2 hours and then poured into H2O. The product was extracted (CHCl3), dried (MgSO4), and concentrated to yield 4.3 g of an oil. The product was triturated with hexane and then recrystallized from CCl4 -hexane twice to yield 2.80 g of product. The product was further purified using high pressure liquid chromatography (silica gel, ethyl acetate)) to yield 2.1 g (45%) of 1-acetyl-4-[1-[4-(trifluoromethyl)phenyl]-1H-indazol-3-yl]piperidine, m.p. 148°-150° C.

Provenance & Evidence