Triphenylphosphine dibromide → 5-Bromo-3-(5-(3-methylthiophen-2-yl)-1,3,4-oxadiazol-2-yl)pyrazin-2-amine

Participants

Reaction Steps

To a suspension of 3-amino-6-bromo-N′-(3-methylthiophene-2-carbonyl)pyrazine-2-carbohydrazide (7.85 g, 22.04 mmol) in anhydrous acetonitrile (117.8 mL) cooled in an ice bath was added DIPEA (8.546 g, 11.52 mL, 66.12 mmol) followed by dibromo(triphenyl)phosphorane (12.09 g, 28.65 mmol) portionwise. The resulting suspension was stirred at room temperature for 30 min and the precipitate isolated by filtration and washed with acetonitrile to give the product as a yellow solid (4.42 g, 52% yield); 1H NMR (400 MHz, DMSO) d 2.64 (s, 3H), 7.21 (d, 1H), 7.91 (3H, m) and 8.44 (s, 1H) ppm; MS (ES+) 340.04

Provenance & Evidence