Dimethyl Sulfoxide → 3-(Bis(tert-butoxycarbonyl)amino)-6-(2,2,2-trifluoro-ethoxy)-pyrazine-2-carboxylic acid methyl ester

Participants

Reaction Steps

A suspension of methyl 3-(bis(tert-butoxycarbonyl)amino)-6-bromopyrazine-2-carboxylate (500 mg, 1.16 mmol), 2,2,2-trifluoroethanol (84 μl, 1.16 mmol), cesium carbonate (415 mg, 1.27 mmol) and dry DMSO (5 ml) was stirred at r.t. for 3 h. The reaction mixture was poured into ethyl acetate (100 ml) and extracted with saturated sodium bicarbonate (aqueous solution). The organic layer was washed with water and brine and the aqueous layers were back-extracted with ethyl acetate. The combined organic layers were dried, evaporated and the product was obtained after purification by silica gel chromatography using a heptane/ethyl acetate gradient as white solid (456 mg, 87%).

Provenance & Evidence