2-Aminopyridine → 3-[3-(2-Chloro-4-pyrimidinyl)imidazo[1,2-a]pyridin-2-yl]benzonitrile

Participants

Reaction Conditions

Reaction Steps

A mixture of tautomers, 3-[(2-chloro-4-pyrimidinyl)acetyl]benzonitrile and 3-[(E)-2-(2-chloro-4-pyrimidinyl)-1-hydroxyethenyl]benzonitrile, (1.56 g, 6.05 mmol) was dissolved in 100 mL of DCM with stirring and cooled to 0° C. NBS (1.08 g, 6.07 mmol) was added and the reaction was allowed to warm to rt. The reaction was stirred for one hour and concentrated in vacuo. The residue was dissolved in dioxane with stirring. 2-Aminopyridine (1.71 g, 18.2 mmol) was added, and the reaction was heated to 60° C. The reaction was stirred overnight and cooled to rt. The reaction was poured into H2O and EtOAc. The layers were separated, and the organic layer was washed with brine. The combined aqueous layers were extracted with DCM (2×) and EtOAc. The combined organic layers were dried over MgSO4, filtered, and concentrated in vacuo. The residue was purified by flash chromatography, and fractions containing product were concentrated in vacuo. The residue was triturated with diethyl ether and hexanes (˜1:1), filtered, and the solid was washed with diethyl ether and hexanes (˜1:1). The solid was collected to provide 1.50 g (75%) of the title compound. 1H NMR (400 MHz, DMSO-d6) δ 9.35 (d, J=7.0 Hz, 1H), 8.60 (d, J=5.3 Hz, 1H), 8.14 (s, 1H), 7.98 (d, J=7.9 Hz, 1H), 7.93 (d, J=7.9 Hz, 1H), 7.81 (d, J=8.8 Hz, 1H), 7.67 (t, J=7.9 Hz, 1H), 7.59 (dd, J=6.8, 1.1 Hz, 1H), 7.31-7.17 (m, 2H).

Provenance & Evidence