Tri-o-tolylphosphine → 1-(t-Butoxycarbonyl)-4-[1-(3-fluoro-4-pyridyl)piperazin-4-ylcarbonyl]piperazine

Participants

Reaction Conditions

Reaction Steps

Tris(dibenzylideneacetone)dipalladium(0) (0.184 g) and tri-o-tolylphosphine (0.244 g) were added to a suspension of 3-fluoro-4-iodopyridine (4.46 g), 1-[1-(t-butoxycarbonyl)piperazin-4-ylcarbonyl]piperazine (3.0 g) and sodium t-butoxide (2.12 g) in dry 1,4-dioxane (40 ml) under an atmosphere of argon. The mixture was heated at 100° C. for 18 hours. The mixture was cooled, diluted with diethyl ether (200 ml) and washed with saturated brine (40 ml). The aqueous layer was back-extracted with diethyl ether (2×100 ml). The ether layers were all combined, washed with saturated brine (2×100 ml), dried (Na2SO4) and evaporated. The residual oil was purified by chromatography on alumina (N32-63) using 0.1-0.4% methanol in dichloromethane as eluent to give 1-(t-butoxycarbonyl)-4-[1-(3-fluoro-4-pyridyl)piperazin-4-ylcarbonyl]piperazine (1.7 g) as an orange solid: NMR (CDCl3): 1.47 (s, 9H), 3.25 (m, 8H), 3.45 (m, 8H), 6.75 (dd, 1H), 8.20 (dd, 2H); m/z 394 (M+1).

Provenance & Evidence