Trimethylsilylacetylene → Ethyl 6-[(trimethylsilyl)ethynyl]imidazo[1,2-a]pyridine-2-carboxylate

Participants

Reaction Conditions

Reaction Steps

A mixture of 4 g of ethyl 6-iodoimidazo[1,2-a]pyridine-2-carboxylate, 2.63 mL of ethynyltrimethylsilane and 888 mg of dichlorobis(triphenylphosphine)palladium is degassed under vacuum. 240 mg of degassed N,N-dimethylformamide and 3.52 mL of triethylamine are added. The reaction mixture is degassed under argon, stirred at 50° C. for 50 hours and then cooled and diluted with 20 mL of water. The precipitate is filtered off by suction and washed with 5 mL of water and then chromatographed on silica, eluting with mixtures of ethyl acetate and hexane (from 50/50 to 90/10). The fractions containing the expected product are combined and concentrated to dryness under reduced pressure to give 3.6 g of ethyl 6-[(trimethylsilyl)ethynyl]imidazo[1,2-a]pyridine-2-carboxylate in the form of an off-white solid.

Provenance & Evidence