5-Fluoroindole-2-carboxylic acid → HCID 489422, compound

Participants

Reaction Steps

1,1'-carbonyldiimidazole (0.48) is added to a 20°-25° solution of 5-fluoroindole-2-carboxylic acid (I, 0.53 g) in THF (6 ml). After 1 hour of stirring the above reaction is added dropwise via cannula to a solution of [3-(propylamino)-2-pyridinyl]piperazine (II, PREPARATION 7, 0.72 g) in THF (6 ml) at -10° (ice/acetone bath). The reaction is stirred for 30 minutes at -10°, slowly warming to 20°-25°, and stirred 4 hours. The reaction is diluted with dichloromethane (50 ml), washed with saturated aqueous sodium bicarbonate (40 ml), saline (40 ml), dried over anhydrous sodium sulfate and concentrated under reduced pressure. The concentrate is purified by flash column chromatography (40 g silica gel) eluting with ethyl acetate/hexane (1/1). The appropriate fractions are pooled and concentrated to give the title compound, mp 196°-198°; IR (mineral oil) 3200, 2920-3000, 1630 and 1424 cm-1 ; NMR (300 MHz, CDCl3) 9.82, 7.72, 7.35, 7.27, 7.03, 6.95, 6.86, 6.78, 4.32, 4.09, 3.21, 3.08, 1.71 and 1.05 δ; CMR (300 MHz, CDCl3) 162.3, 159.5, 149.7, 137.4, 135.1, 132.3, 130.7, 127.5, 127.4, 120.4, 116.3, 113.4, 112.9, 112.7, 112.5, 106.1, 105.8, 105.1, 105.0, 49.0, 45.2, 22.5 and 11.6 δ; MS (m/e) 382, 381, 190, 176, 164, 162, 134 and 120.

Provenance & Evidence