A mixture of 2-chloronicotinic acid (113 mg, 0.72 mmol), potassium carbonate (199 mg, 1.44 mmol), 3-cyclopentyl-1-(2-methylphenyl)-1H-pyrazol-5-amine (174 mg, 0.72 mmol) (Intermediate E), and copper (II) acetate (6.5 mg, 0.04 mmol) in DMF (3 mL) was heated (150° C.) in a sealed tube for 16 h. The mixture was cooled to rt, filtered through a silica gel plug using ethyl acetate as eluent, concentrated to dryness, and subjected to HPLC purification using a gradient elution from 30% to 90% acetonitrile in water to afford 59.7 mg (23%) of the desired product.
