Toluene → tert-butyl 1-phenyl-8,9-dihydro-3H-pyrazolo[3,4-c][2,7]naphthyridine-7(6H)-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of tert-butyl 1-bromo-8,9-dihydro-3H-pyrazolo[3,4-c][2,7]naphthyridine-7(6H)-carboxylate (0.540 g, 1.53 mmol) in toluene (8 mL) and ethanol (4 mL) was added phenyl bronic acid (0.371 g, 3.07 mmol) followed by Na2CO3 (0.96 g, 9.18 mmol) as a solution in water (10 mL). The mixture was vortexed and 1,1-Bis(Di-t-butylphosphino)Ferrocene Palladium dichloride (BDtPFPdCl2, CAS#95408-45-0, 0.025 g) was added to the reaction mixture. The reaction was then purged with nitrogen and heated at 90° C. for 16 hours. On completion of the reaction, EtOAc (50 mL) and water (50 mL) was added. The organic layer was separated, washed with brine (2×20 mL), dried (Na2SO4), filtered and concentrated under reduced pressure to give the crude product. The crude product was purified using flash column chromatography (SiO2, 50% EtOAc in hexane) to give the pure desired product, tert-butyl 1-phenyl-8,9-dihydro-3H-pyrazolo[3,4-c][2,7]naphthyridine-7(6H)-carboxylate (0.278 g, 52%) as a white foamy solid. M.p.=>65° C.; 400 MHz 1H NMR (DMSO-d6) δ: 13.72 (s, 1H), 8.38 (s, 1H), 7.73-7.62 (m, 2H), 7.56-7.42 (m, 3H), 4.65 (s, 2H), 3.54-3.45 (m, 2H), 2.88-2.8 (m, 2H), 1.44 (s, 9H); LCMS [M+H]: 351.

Provenance & Evidence