4-(Bromomethyl)benzoic acid → 5-Bromo-3-(5-(4-(bromomethyl)phenyl)-1,3,4-oxadiazol-2-yl)pyrazin-2-amine

Participants

Reaction Steps

Dibromo(triphenyl)phosphorane (37.29 g, 88.35 mmol) was added to a suspension of 4-(bromomethyl)benzoic acid (4.318 g, 20.08 mmol) and 3-amino-6-bromo-pyrazine-2-carbohydrazide (4.66 g, 20.08 mmol) in acetonitrile (143.4 mL). The resulting mixture was stirred at room temperature for 2 h and then Hunig's base (15.57 g, 20.98 mL, 120.5 mmol) was added and the reaction was stirred overnight. Exotherm observed during Hunig's base addition; moderated with ice bath (temp. kept around 20+/−4). The reaction mixture was filtered and the solid obtained washed with cold acetonitrile to leave the product as a yellow solid (5.45 g, 66.7% yield); 1H NMR (400.0 MHz, DMSO) d 4.82 (s, 2H), 7.72 (d, 2H), 7.80 (s, 1H), 8.11 (d, 2H) and 8.45 (s, 1H) ppm; MS (ES+) 412.1.

Provenance & Evidence