Triphenylphosphine → n-Tert-butyl-1-cyano-n-methyl-1-[(r)-3-(1-methyl-2-pyrrolidinylmethyl)-1-tosyl-1h-indol-5-yl]methanesulfonamide

Participants

Reaction Conditions

Reaction Steps

To a stirred suspension of dichlorobis(triphenylphosphine)palladium (II) (704 mg, 1 mmol) and triphenylphosphine (525 mg, 2 mmol) in ethyleneglycol dimethylether (5 ml) at ambient temperature under an atmosphere of nitrogen was added sodium borohydride (38 mg, 1 mmol) in one portion. The green slurry was stirred for 5 min, then N-tert-butyl-cyano-N-methylmethanesulfonamide (from step (c), 1.04 g, 5.4 mmol) was added in one portion. The green slurry was then cooled to 0-5° C. and sodium hydride (60% dispersion in mineral oil) (441 mg, 11 mmol) was added portionwise, maintaining the temperature below 5° C. The brown solution was then warmed to ambient temperature over a 10 min period, before a solution of (R)-5-bromo-3-(1-methyl-2-pyrrolidinylmethyl)-1-tosyl-1H-indole (from step (d), 2.24 g, 5 mmol) in ethyleneglycol dimethyl ether (15 ml) was added dropwise. The brown slurry was then warmed to reflux. Reflux was maintained for 1.5 hr after which time the dark brown solution was cooled to ambient temperature. The reaction mixture was then poured into water (20 ml) and extracted with ethyl acetate (3×25 ml). The organic extracts were combined and evaporated in vacuo to yield a brown oil. This was purified by flash column chromatography (ethyl acetate:hexane:diethylamine 1:1:0.1 as eluant) to yield the subtitle compound (1.23 g, 45%) as a golden oil.

Provenance & Evidence