Triethylamine → 5-(2-(Trimethylsilyl)ethynyl)pyridin-2-amine

Participants

Reaction Conditions

Reaction Steps

A mixture of commercially available 2-amino-5-bromopyridine (50.0 g, 289 mmol), trimethylsilylacetylene (112 mL, 809 mmol), Et3N (120 mL, 867 mmol), PdCl2(PPh3)2 (4.06 g, 2 mol %) and PPh3 (1.52 g, 2 mol %) in DMF (290 mL) was purged for 10 min with argon. Then CuI (340 mg, 1 mol %) was added and the reaction mixture was heated up to 90° C., stirring was continued at 90° C. for 4.5 h. Cooled to 23° C., the reaction mixture was concentrated in vacuum to remove all volatiles, poured the residue onto water (300 mL) and extracted with ethyl acetate (3×500 mL). The combined organic layers were washed with water (300 mL) and brine (2×250 mL), dried over MgSO4. Removal of the solvent in vacuum left a dark brown residue which was purified by flash chromatography with n-heptane and acetone to give the title compound as a brown solid (41.65 g, 76%). MS (ISP) 191 [(M+H)+].

Provenance & Evidence