Sodium Carbonate → 2-[5-(4-Cyanophenyl)-furan-2-yl]-imidazo[1,2-a]pyridine-6-carbonitrile

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of 3a (10 mmol), and tetrakis(triphenylphosphine) palladium (350 mg) in toluene (20 mL) under a nitrogen atmosphere was added 10 mL of a 2 M aqueous solution of Na2CO3 followed by 4-Cyanophenyl boronic acid (12 mmol) in 10 mL of methanol. The vigorously stirred mixture was warmed to 80° C. for 24 h, then cooled, and the precipitate was filtered. The precipitate was partitioned between methylene chloride (500 mL) and 2 M aqueous Na2CO3 (50 mL) containing 6 mL of concentrated ammonia. The organic layer was dried (Na2SO4), and then concentrated to dryness under reduced pressure to afford 4a. Yield 82%, mp 298-300° C. (DMF). 1H NMR (DMSO-d6); δ 7.11 (d, J=3.6 Hz, 1H), 7.37 (d, J=3.6 Hz, 1H), 7.53 (d, J=9.6 Hz, 1H), 7.72 (d, J=9.6 Hz, 1H), 7.90 (d, J=8.4 Hz, 2H), 7.98 (d, J=8.4 Hz, 2H), 8.45 (s, 1H), 9.32 (s, 1H). 13C NMR; δ 152.0, 150.4, 145.1, 138.6, 135.0, 134.4, 133.6, 126.1, 124.6, 119.5, 118.0, 117.6, 112.2, 111.3, 110.2, 98.1. MS (m/z, rel.int.); 310 (M+, 100), 281 (10), 208 (5), 180 (10). High resolution mass calcd. for C19H10N4O: 310.08546. Observed: 310.07852. Anal. Calcd. for 4a (C19H10N4O): C % 73.54, H % 3.25, N % 18.06. Found: C % 73.28, H % 3.26, N % 17.75.

Provenance & Evidence