Lithium Chloride → HCID 117738000, compound

Participants

Reaction Conditions

Reaction Steps

Methyl 4-[(5-bromopyrazin-2-yl)amino]-4-oxo-butanoate (A2, 1.00 g, 3.47 mmol) was dissolved in toluene in a microwave vial and lithium chloride, (0.178 g, 4.17 mmol), palladium triphenylphosphone tetrakis (0.405 g, 0.347 mmol) and tributyl(1-ethoxyvinyl)stannane (1.88 g, 5.21 mmol) were added. The reaction mixture was heated in a sealed vial overnight at 100° C. The mixture was diluted with ethyl acetate and washed with water. The organic layer was dried over Na2SO4, and the solvent were evaporated. The product was purified by flash chromatography (AcOEt/cyclohexane: 1/99→99/1) to give methyl 4-[[5-(1-ethoxyvinyl)pyrazin-2-yl]amino]-4-oxo-butanoate (0.36 g, 1.3 mmol, 37% Yield). This product (0.34 g, 1.2 mmol) was dissolved in tetrahydrofuran (2.20 g, 2.4 mL) and hydrochloric acid (1.2 mL, 2.4 mmol. 2M) was added. After 1 h, brine was added to the mixture and it was extracted 3 times with ethyl acetate. The combined organic layers were dried over MgSO4 and evaporated. The product was purified by flash chromatography (AcOEt/cyclohexane: 1/99→99/1) to give methyl 4-[(5-acetylpyrazin-2-yl)amino]-4-oxo-butanoate A34 (0.14 g, 0.56 mmol, 46% Yield). 1H NMR (400 MHz, CDCl3) 9.52 (1H, s), 9.19 (1H, s), 8.88 (1H, s), 3.70 (3H, s), 2.88-2.75 (2H, m), 2.58 (3H, s).

Provenance & Evidence