Trimethylsilylacetylene → 5-Bromo-3-((trimethylsilyl)ethynyl)pyrazin-2-amine

Participants

Reaction Conditions

Reaction Steps

To a solution of 3,5-dibromopyrazin-2-amine (10 g, 40 mmol), copper(I) iodide (0.91 g, 4.7 mmol), diisopropylethylamine (53 mL, 0.55 mol), and tetrakis(triphenylphosphine)-palladium(0) (2.3 g, 1.9 mmol) in DMF (120 mL) that was de-gassed with Ar was added trimethylsilylacetylene (6.7 mL, 48 mmol). The resulting mixture was stirred under an Ar atmosphere for 1 h at 120° C., after which it was evaporated to dryness in vacuo. The residue was subjected to silica gel chromatography eluting with 35% EtOAc in hexanes to give a brown oil that was triturated with hexanes to give the title compound (5.0 g, 47%). 1H NMR (CDCl3, 300 MHz): δ 8.04 (s, 1H), 5.10 (s, 2H), 0.28 (s, 9H). HPLC retention time: 2.75 minutes. MS ESI (m/z): 270.0, 272.0 (M+H)+, calc. 269.

Provenance & Evidence