2,2-Difluoroacetohydrazide → 7-bromo-1-(difluoromethyl)-8-phenyl-4H-pyrido[2,3-b][1,2,4]triazolo[4,3-d][1,4]oxazine

Participants

Reaction Steps

A mixture of 6-bromo-7-phenyl-1H-pyrido[2,3-b][1,4]oxazine-2(3H)-thione (0.21 g, 0.654 mmol) and 2,2-difluoroacetohydrazide (0.14 g, 1.3 mmol) in xylene (6 ml) was heated at 150 degree under microwave for 60 min. The reaction solution was concentrated and the residue was partitioned between ethyl acetate (10 ml) and water (10 ml). The organic phase was separated and the aqueous phase was extracted with ethyl acetate (10 ml). The combined organic phase was concentrated and purified by column (biotage 25 g) eluted with ethyl acetate/cyclohexane (0-60%) to afford product (55 mg). 1H NMR (500 MHz, CDCl3) 8.09 (s, 1H), 7.4-7.55 (m, 5H), 7.06 (t, 1H), 5.66 (s, 2H).

Provenance & Evidence