To a solution of tert-butyl 4-(2-(5-tosyl-5H-pyrrolo[2,3-b]pyrazin-2-yl)hydrazinecarbonyl)-bicyclo[2.2.2]octan-1-ylcarbamate (6.1 g, 11.0 mmol), TEA (6.1 mL, 44.0 mmol) in 1,4-dioxane (110 mL) was added SOCl2 (2.0 mL, 27.5 mmol). The reaction mixture was heated at about 80° C. for about 2 h then cooled to ambient temperature. The reaction mixture was washed with saturated aqueous NaHCO3 (3×50 mL). The aqueous portion was filtered to give 4-(6-tosyl-6H-pyrrolo[2,3-e][1,2,4]triazolo[4,3-a]pyrazin-1-yl)bicyclo[2.2.2]-octan-1-amine as a brown solid (1.17 g, 24%): LC/MS (Table 1, Method a) Rt=1.28 min; MS m/z: 437 (M+H)+. The remaining filtrate was extracted with EtOAc (10 mL). The organic layer was dried over anhydrous MgSO4, filtered, and concd under reduced pressure to afford crude tert-butyl 4-(6-tosyl-6H-pyrrolo[2,3-e][1,2,4]triazolo[4,3-a]pyrazin-1-yl)bicyclo[2.2.2]octan-1-ylcarbamate (3.5 g). The crude Boc-protected material was dissolved in 1,4-dioxane (38 mL) and HCl (4 N in 1,4-dioxane, 8 mL) was added. The reaction mixture was heated at about 50° C. for about 3 h. The precipitate formed was filtered, dissolved in DCM (50 mL), and washed with saturated aqueous NaHCO3 (3×20 mL). The layers were separated and the organic portion was dried over anhydrous MgSO4, filtered, and concd under reduced pressure to give additional 4-(6-tosyl-6H-pyrrolo[2,3-e][1,2,4]triazolo[4,3-a]pyrazin-1-yl)bicyclo[2.2.2]octan-1-amine as a brown solid (2.3 g, 50% over 2 steps): LC/MS (Table 1, Method a) Rt=1.28 min; MS m/z: 437 (M+H)+.
