To a solution of 3,5-dibromo-pyrazin-2-ylamine (252 mg, 1.00 mmol) in DME (10 mL) 60% NaH (120 mg, 3.00 mmol) was added portion wise. The resulting mixture was stirred at room temperature for 30 min and then treated with 5-tert-butyl-4-chloro-2-methyl-2H-pyrazole-3-carbonyl chloride (234 mg, 1.00 mmol, prepared as described in Example 1, STEP C). The resulting mixture was stirred at room temperature for 2 h and treated with saturated NH4Cl (20 mL) followed by EtOAc (20 mL). The organic layer was separated, dried (Na2SO4) and concentrated. The resulting residue was dissolved in 1,4-dioxane (10 mL) and treated with 4-methoxybenzylamine (0.650 mL, 5.00 mmol). The resulting mixture was stirred at 65° C. for 2 h. The resulting mixture was allowed to cool to room temperature and then treated with water (10 mL) and EtOAc (20 mL). The organic layer was separated, dried (Na2SO4) and concentrated. The resulting residue was purified on silica (0:100-50:50 EtOAc:hexane) to yield 5-tert-butyl-4-chloro-2-methyl-2H-pyrazole-3-carboxylic acid [5-bromo-3-(4-methoxy-benzylamino)-pyrazin-2-yl]-amide. 1H-NMR (400 MHz, CDCl3) δ: 8.77 (br. s., 1H), 7.70 (s, 1H), 7.34 (d, J=8.6 Hz, 2H), 6.88 (d, J=8.6 Hz, 2H), 6.28-6.36 (m, 1H), 4.59 (d, J=5.1 Hz, 2H), 4.08 (s, 3H), 3.80 (s, 3H), 1.40 (s, 9H).
