To a mixture of 4-(3-amino-6-(ethoxycarbonyl)pyrazin-2-yl)-2-fluorobenzoic acid (0.214 g, 0.7 mmol), (S)-2-amino-2-(3-bromo-5-fluorophenyl)ethanol (272 mg, 1.009 mmol),HOAt (187 mg, 1.376 mmol) and EDC (264 mg, 1.376 mmol) in DMF (2.5 mL) was added DIEA (0.961 mL, 5.50 mmol). The resultant mixture was stirred over night at RT. The mixture was diluted with EtOAc, washed with water three times and brine, dried, concentrated to afford the crude product as a light yellow viscous liquid. ISCO purification (12 g silica, 10 to 90% EtOAc in heptane, 30 min) provided the desired product (200 mg, 84% yield) as a light yellow liquid. LC-MS (m/z): 522.9 (MH+), 0.787 min.
