Ethyl orthopropionate → 7-bromo-1-ethyl-8-phenyl-4H-pyrido[2,3-b][1,2,4]triazolo[4,3-d][1,4]oxazine

Participants

Reaction Conditions

Reaction Steps

In a 10 ml microwave vial was (E)-6-bromo-2-hydrazono-7-phenyl-2,3-dihydro-1H-pyrido[2,3-b][1,4]oxazine (90 mg, 0.282 mmol) in 1,1,1-triethoxypropane to give a yellow suspension. The reaction mixture was heated to 120° C. for 20 minutes. The crude residue was concentrated under reduced pressure and purified by Biotage silica gel chromatography (gradient 100% to 100% n-hexane in ethyl acetate) to give the title compound (41 mg, 40%). 1H NMR (500 MHz, CDCl3): 7.73 (1H, s), 7.54-7.48 (3H, m), 7.45-7.41 (2H, m), 5.56 (2H, s), 3.10-3.00 (2H, q), 1.53-1.48 (3H, t). LCMS (Method D) RT 1.117 min, M+1=358.

Provenance & Evidence