Potassium Carbonate → 3-Methylbenzo[f][1,7]naphthyridin-5-amine

Participants

Reaction Conditions

Reaction Steps

A solution of 2-(tert-butoxycarbonylamino)phenylboronic acid (1.0 eq.) and 3-bromo-6-methylpicolinonitrile (from step 2) (1.0 eq.) in toluene (0.44 M) was mixed with tetrakis(triphenyl-phosphine)palladium (5 mol %) and 2N aqueous potassium carbonate solution (2.0 eq.). The reaction was heated to 100° C. and stirred overnight. After cooling to ambient temperature, the reaction content was diluted with 2% methanol in dichloromethane and water. The two phases were separated, and the aqueous layer was extracted twice with 2% methanol in dichloromethane. The combined organic layers were washed with brine, dried over anhydrous MgSO4, and concentrated en vacuo. The crude product was purified by flash chromatography on a COMBIFLASH® system (ISCO) using 0-70% ethyl acetate in hexane to give 3-methylbenzo[f][1,7]naphthyridin-5-amine as a yellow solid. 1H NMR (methanol d-4): δ 8.85 (d, 1H), 8.38 (d, 1H), 7.72 (d, 1H), 7.53-7.61 (m, 2H), 7.34-7.38 (dd, 1H), 2.76 (s, 3H). LRMS [M+H]=210.1

Provenance & Evidence