4-Aminopyridine → HCID 54204103, compound

Participants

Reaction Steps

46 μL (0.629 mmol, 1.3 equiv) thionyl chloride were added to a room temperature solution of 125 mg (0.484 mmol, 1.0 equiv) 1-cyclopentyl-3-ethyl-1H-indazole-6-carboxylic acid and 5 μL DMF in 5 mL anhydrous toluene. The reaction mixture was heated to reflux for 2 hours, then cooled to room temperature, concentrated to dryness on a rotary evaporator, and dried at high vacuum, room temperature for several hours. The crude acid chloride was dissolve din 5 mL anhydrous pyridine, 50 mg (0.532 mmol, 1.1 equiv) 4-aminopyridine were added, and the mixture heated to 40° C. for 1 hour. The reaction mixture was cooled to room temperature and allowed to stand overnight. 10 mL H2O were added, and the mixture was concentrated to dryness on a rotary evaporator. The residue was taken up in 50 mL H2O and 25 mL CH2Cl2, and the layers separated. The aqueous layer was extracted 1×25 mL CH2Cl2. The organic extracts were combined, washed 1×10 mL each H2O, brine, and dried over Na2SO4. Filtration, concentration of filtrate and drying gave 133 mg of a white foam, which was purified on a silica gel column (25% CH3OH/CH2Cl2) to give 122 mg of white needles. Recrystallization from ethyl acetate/hexanes gave 101 mg (62%) of white shiny plates: mp 144-146° C.; Anal. calcd for C20H22N4O: C, 71.83; H, 6.63; N, 16.75. Found: C, 72.00; H, 7.03; N, 16.16.

Provenance & Evidence