Cesium carbonate → [2-(3-Methoxy-phenyl)-[1,2,4]triazolo[1,5-a]pyridin-7-yl]-carbamic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

A solution of 7-bromo-2-(3-methoxy-phenyl)-[1,2,4]triazolo[1,5-a]pyridine (5.0 g, 16.4 mmol), tert-butyl carbamate (2.88 g, 24.7 mmol) and cesium carbonate (10.6 g, 32.9 mmol) in dioxane (85 ml) was degassed well with argon for 20 min at 25° C. To this solution was then added tris(dibenzylideneacetone)dipalladium(0) (3.0 g, 3.28 mmol) and xantphos (3.8 g, 6.57 mmol), and the resulting mixture was degassed again with argon for another 20 min. The reaction mixture was heated at 100° C. under argon atmosphere for 16 h. The reaction mixture was diluted with EtOAc (500 ml). The organic layer was washed successively with water (2×250 ml) and brine (100 ml), dried over anhydrous Na2SO4, filtered, and evaporated in vacuum. The crude material thus obtained was purified by column chromatography over silica gel (20-40% EtOAc/hexane) to afford [2-(3-methoxy-phenyl)-[1,2,4]triazolo[1,5-a]pyridin-7-yl]-carbamic acid tert-butyl ester (2.8 g, 51%) as yellow solid. LC-MS: m/z=341 [M+H]+.

Provenance & Evidence