A mixture of 2,6-diiodopyrazine (1 g, 3.013 mmol), tert-butyl (2S)-2-isobutylpiperazine-1-carboxylate (949.3 mg, 3.917 mmol) and K2CO3 (624.7 mg, 4.520 mmol) in DMF (5 mL) was heated to 90° C. and stirred for 17 hrs. It was then allowed to cool and diluted with ethyl acetate and water, further washed organic layer with water and brine, dried (MgSO4) and concentrated to give an orange oil. It was then columned on silica gel eluting with 1:1 EtOAc/hexanes to give (S)-tert-butyl 4-(6-iodopyrazin-2-yl)-2-isobutylpiperazine-1-carboxylate as a yellow oil 1.05 g, 78%). ES+ 447. 1HNMR (CDCl3) 0.98 (6H, d), 1.23-1.45 (2H, m), 1.55-1.63 (1H, m), 2.91-3.00 (1H, m), 3.03-3.21 (2H, m), 3.98-4.20 (3H, m), 4.25 (1H, brs), 7.95 (1H, s), 8.06 (1H, s).
