1H-Indazole-4-boronic acid → 3-Hydroxy-6'-(1H-indazol-4-yl)-4H-1,2'-bipyridin-4-one

Participants

Reaction Conditions

Reaction Steps

A mixture of 6′-bromo-3-[(4-methoxybenzyl)oxy]-4H-1,2′-bipyridin-4-one (40 mg, 0.1 mmol), 1H-indazol-4-ylboronic acid (32.5 mg, 0.2 mmol), and 1,1′-bis(diphenylphosphino)ferrocene-palladium(II)dichloride dichchloromethane complex (4 mg) in THF (2 mL) and 1 M aq. Cs2CO3 (1 mL) was heated under microwave irradiation at 160° C. for 10 min. After cooling to rt, the THF and aq. layers were separated and the aq. solution was extracted with THF (2×2 mL). The combined THF solution was treated with QuadraPure TU resin (Aldrich) for 1 h and filtered. The collected THF solution was concentrated. The concentrated residue was dissolved in TFA-DCM (1:1, 1 mL) and stirred for 1 h. The TFA-DCM solution was concentrated and the residue was purified by LCMS to give 3-Hydroxy-6′-(1H-indazol-4-yl)-4H-1,2′-bipyridin-4-one (TFA salt,). 1H NMR (499 MHz, DMSO): δ 8.60-8.55 (m, 2 H); 8.39 (d, J=2.4 Hz, 1 H); 8.18 (t, J=7.9 Hz, 1 H); 8.10 (d, J=7.7 Hz, 1 H); 7.87 (d, J=8.1 Hz, 1 H); 7.82 (d, J=7.2 Hz, 1 H); 7.70 (d, J=8.3 Hz, 1 H); 7.52 (t, J=7.7 Hz, 1 H); 6.50 (d, J=7.6 Hz, 1 H); LC/MS (M+H)+ 305; HRMS Calcd for (C17H12N4O2+H)+ 305.1033 found 305.1032.

Provenance & Evidence