Cesium carbonate → Tert-butyl 2-isopropyl-[1,2,4]triazolo[1,5-a]pyridin-7-ylcarbamate

Participants

Reaction Steps

To an argon purged solution of 7-bromo-2-isopropyl-[1,2,4]triazolo[1,5-a]pyridine (378 mg, 1.57 mmol) in dioxane (10 ml) are added tert-butyl carbamate (221 mg, 1.89 mmol), cesium carbonate (718 mg, 2.2 mmol), tris(dibenzylideneacetone)dipalladium(0) (28.8 mg, 31.5 μmol) and 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (36.4 mg, 63.0 μmol). The resulting mixture is refluxed for 2.5 days (weekend) under argon atmosphere. The crude material is loaded on silicagel and purified by flash chromatography on a 20 g silica column using heptane/ethyl acetate 20-70% as eluent affording tert-butyl 2-isopropyl-[1,2,4]triazolo[1,5-a]pyridin-7-ylcarbamate (405 mg, 93.1%) as a light yellow solid. Mp.: 215-8° C. MS: m/z=277.1 (M+H+).

Provenance & Evidence