4-(Bromomethyl)benzoic acid → 1-[4-[5-Amino-6-[5-[4-(bromomethyl)phenyl]-1,3,4-oxadiazol-2-yl]pyrazin-2-yl]-1-piperidyl]propan-1-one

Participants

Reaction Steps

Dibromo(triphenyl)phosphorane (682 mg, 1.6 mmol) was added to a suspension of 3-amino-6-(1-propanoyl-4-piperidyl)pyrazine-2-carbohydrazide (105 mg, 0.36 mmol) and 4-(bromomethyl)benzoic acid (77 mg, 0.36 mmol) in MeCN (2 mL) at room temperature and the resulting solution was stirred for 1 h under an atmosphere of nitrogen. DIPEA (278.5 mg, 375.3 μL, 2.155 mmol) was added dropwise and the solution was stirred for 2 h. The reaction mixture was diluted with ethyl acetate, washed with 50% saturated sodium bicarbonate solution (2×20 mL), water, and brine. The solution was dried over anhydrous Na2SO4, filtered, concentrated in vacuo to obtain 1-[4-[5-amino-6-[5-[4-(bromomethyl)phenyl]-1,3,4-oxadiazol-2-yl]pyrazin-2-yl]-1-piperidyl]propan-1-one, which was taken to the next step without further purification.

Provenance & Evidence