Diisopropylamine → HCID 89444279, compound

Participants

Reaction Steps

A solution of methyl 4-[(5-bromopyrazin-2-yl)amino]-4-oxo-butanoate (A2, 1.0 g, 3.5 mmol), copper iodide (0.17 mmol, 0.033 g), diisopropylamine (4.2 mmol, 0.42 g, 0.59 mL) and palladium(II)bis(triphenylphosphine)dichloride (0.17 mmol, 0.12 g) in tetrahydrofuran (30 mL) was degassed with Ar. Then ethynyl(trimethyl)silane (7.60 mmol, 0.75 g, 1.1 mL) was added slowly and the mixture was stirred overnight. The mixture was filtered through a pad of celite which was washed with ethyl acetate and filtrate was concentrated under reduced pressure. The product was purified by flash chromatography (ethyl acetate/cyclohexane: 1/99→99/1) to give methyl 4-oxo-4-[[5-(2-trimethylsilylethynyl)pyrazin-2-yl]amino]butanoate (E, 0.85 g, 2.8 mmol, 80% Yield). 1H NMR (400 MHz, CDCl3) 9.46 (1H, s), 9.00 (1H, s), 8.33 (1H, s), 3.71 (3H, s), 2.88-2.75 (2H, m), 0.20 (9H, s).

Provenance & Evidence