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

Participants

Reaction Conditions

Reaction Steps

To a 500 ml three necked round bottom flask, 3,5-dibromopyrazine-2-amine (25.0 g, 0.0988 mole) was taken in acetonitrile (250 ml). The reaction mixture was cooled to 0° C. and triethylamine (50.0 g, 0.4941 mole), copper (1) iodide (2.26 g, 0.0119 mole), and Pd(PPh3)4 (5.7 g, 0.0049 mole) were added under nitrogen atmosphere. The reaction mixture was stirred for 10 min at 0° C. followed by slow addition of trimethylsilylacetylene (10.7 g, 0.1089 mole) over 15 min at the same temperature. After completion of the addition, the reaction mixture was warmed up to RT and stirred for 90 min. The completion of the reaction was monitored on TLC using hexanes:ethyl acetate (5:5) as a mobile phase. After completion of the reaction, the reaction mixture was diluted by ethyl acetate and filtered through high flow. Filtrate was collected and washed with water. Layers were separated and aq. layer was re-extracted by ethyl acetate. Combined organic layer was dried over Na2SO4, filtered and concentrated to afford crude product which was subjected for the column purification. The crude compound was purified using column purification by eluting the compound with 7-10% ethyl acetate in hexanes to yield 20.0 g of 5-bromo-3-((trimethylsilyl)ethynyl)pyrazine-2-amine.

Provenance & Evidence