Cesium carbonate → Ethyl 7-(tert-butoxycarbonylamino)-[1,2,4]triazolo[1,5-a]pyridine-2-carboxylate

Participants

Reaction Conditions

Reaction Steps

To an argon purged solution of ethyl 7-bromo-[1,2,4]triazolo[1,5-a]pyridine-2-carboxylate (1.76 g, 6.52 mmol) in dioxane (45 ml) are added tert-butyl carbamate (916 mg, 7.82 mmol), tris(dibenzylideneacetone)dipalladium(0) (119 mg, 130 μmol), 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (151 mg, 261 μmol) and cesium carbonate (2.97 g, 9.12 mmol). The resulting mixture is heated to 110° C. and stirred for 20 hours. The reaction mixture is loaded on silica and purified by flash chromatography on a 50 g silica column using heptane/ethyl acetate 30-100% as eluent affording ethyl 7-(tert-butoxycarbonylamino)-[1,2,4]triazolo[1,5-a]pyridine-2-carboxylate (1.07 g, 54%) as a light yellow solid. mp.: 220-2° C. MS: m/z=307.3 (M+H+).

Provenance & Evidence