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 a 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 suspension of the indazole (4.3 g, 0.012 moles) and triethylamine (3.5 ml, 0.025 moles) in toluene (50 ml) was added dimethylcarbamyl chloride (1.26 ml, 0.014 moles). The reaction was stirred at ambient temperature for 21 hours. The mixture was then poured into H2O, extracted (CHCl3), dried (MgSO4), and concentrated to yield 5.08 g of an oil. The product was purified by high pressure liquid chromatography (HPLC) [silica gel, 100% ethyl acetate] to yield 3.6 g of product as an oil which crystallized upon standing. The product was washed with hexane and dried to yield 3.2 g (62%) of N,N-dimethyl-4-[1-[4-(trifluoromethyl)phenyl]-1H-indazol-3-yl]piperidine-1-carboxamide, m.p. 117°-119° C.

Provenance & Evidence