To a solution of benzyl (3R,4S)-3-{[5-(2,4-dichlorophenyl)-3,6-diethylpyrazin-2-yl]amino}4-ethoxypyrrolidine-1-carboxylate (8.60 g, 15.8 mmole) in CH2Cl2 (0.1M, 158 ml) under N2 was added Palladium chloride (279 mg, 1.58 mmole) and triethyl amine (3.29 ml, 1.5 eq.). Triethylsilane (3.78 ml, 1.5 eq.) was added dropwise over 15 min. After one hour an additional 8.74 ml of triethylsilane was added dropwise. After 2 additional hours, the reaction mixture was filtered through celite. Trifluoroacetic acid (8 ml) was added and the reaction mixture was stirred for 30 min. Quenched to pH 10 with 2N NaOH and extracted 3×300 ml of CH2Cl2, dried MgSO4, filtered and concentrated. Vacuum chromatography was run on a 1 L frit funnel with 5–15% MeOH/CH2Cl2 with 0.5% NH4OH to give 5.95 g (92%) of an oil. 1H NMR (400 MHz, CDCl3) δ) 7.49, 7.33–7.26, 5.38, 4.54, 4.07, 3.68, 3.52, 3.22, 2.95, 2.71, 2.46, 1.29, 1.15; HRMS (FAB) calcd for C20H26Cl2N4O+H 409.1562. found 409.1567. Anal. Calcd for C20H26Cl2N4O: C, 58.68; H, 6.40; N, 13.69. Found: C, 58.42; H, 6.43; N, 13.50.
