反应详情

A solution of 2-amino-5-bromopyridine (0.200 g, 1.16 mmol 1.0 equiv), in 5 mls of methylene chloride, under argon, was treated with trimethylaluminum (0.312 mL, 2.0N in hexanes, 4.0 equiv) at room temperature for 30 min. To the solution was added ethyl-3-methylpyrazole-5-carboxylate (0.356 g, 2.0 equiv). After 4 hrs, the volatile was evaporated, and the residue was redissolved into EtOAc, washed with 0.5N HCl, 0.2 N K2CO3, and saturated aqueous NaCl. The organic layer was dried over Na2SO4, filtered, evaporated and purified via flash chromatography on silica gel to give N-(5-bromo-2-pyridinyl)-(3-methyl)-5-pyrazolecarboxamide (0.160 g, 49%). MS found for C10H9BrN4O (M+H)+: 281, 283.

1. customthe volatile was evaporated
2. dissolutionthe residue was redissolved into EtOAc
3. washwashed with 0.5N HCl, 0.2 N K2CO3, and saturated aqueous NaCl
4. dry with materialThe organic layer was dried over Na2SO4
5. filtrationfiltered
6. customevaporated
7. custompurified via flash chromatography on silica gel