To a solution of 5-pyridin-2-yl-4-quinolin-4-yl 2H-pyrazol-3-ol (50 mg, 0.17 mmol), ethylene glycol (15 mg, 0.24 mmol) and tri-n-butylphosphine (100 mg, 0.50 mmol) in tetrahydrofuran (15 mL) is added 1,1′-(azodicarbonyl)dipiperidine (120 mg, 0.48 mmol). The solution is heated at reflux for 5 h, cooled, and filtered through an SCX cartridge. The residue is chromatographed on SiO2 (15:1 dichloromethane:methanol). The product residue is converted to the disoxylate salt to give the title compound 40 mg (46%).
