Acetic Anhydride → 5-Bromo-4-(2,2,2-trifluoro-ethoxy)-pyridine-2-carboxylic acid [1-cyclopropyl-1-(5-methyl-[1,2,4]oxadiazol-3-yl)-ethyl]-amide

Participants

Reaction Steps

To a solution of 5-Bromo-4-(2,2,2-trifluoro-ethoxy)-pyridine-2-carboxylic acid [1-cyclopropyl-1-(N-hydroxycarbamimidoyl)-ethyl]-amide (Example 78f, 800 mg, 1.88 mmol) in dry DMF (10 ml) was added triethylamine (190 mg, 262 μl, 1.88 mmol) followed by addition of acetic anhydride (192 mg, 1.88 mmol). The reaction mixture was stirred at room temperature for 1 hours and was then stirred at 125° C. for 30 min under microwave radiation. DMF was removed in vacuo and the residue was dissolved in ethylacetate which was extracted with an 1.0M aqueous solution of sodium bicarbonate. The organic phase was dried over sodium sulfate and evaporated down to dryness. The crude material was purified by flash chromatography on silica eluting with a heptane/ethylacetate gradient to yield the title compound (492 mg, 47%) as a light yellow oil. MS (ESI, m/z): 449.3 (M+H+).

Provenance & Evidence