Cesium carbonate → tert-Butyl methyl(1-(5-(thiophen-2-yl)tetrazolo[1,5-a]pyrazin-8-yl)azetidin-3-yl)carbamate

Participants

Reaction Conditions

Reaction Steps

A 3 L round bottom flask was charged with tert-butyl (1-(5-bromotetrazolo[1,5-a]pyrazin-8-yl)azetidin-3-yl)(methyl)carbamate (50 g, 0.13 mol), thiophene-2-boronic acid (22 g, 0.17 mol), tetrakis(triphenylphosphine)palladium(0) (5.0 g, 4.3 mmol), Cs2CO3 (50 g, 0.15 mol), 1,4-dioxane (1.5 L) and water (500 mL). After the air was purged by bubbling N2 into the solution, the resulting solution was stirred at 80° C. under N2 for 14 h. Work-up: the reaction mixture was concentrated in vacuo. The residue was purified by flash column chromatography on silica gel with 0-25% ethyl acetate in CH2Cl2, and then crystallized from methanol, to afford 35 g (70%) of the product as a yellow solid.

Provenance & Evidence