Hydrazinecarboxylic acid, ethyl ester → 7-bromo-8-phenyl-2,4-dihydro-1H-pyrido[2,3-b][1,2,4]triazolo[4,3-d][1,4]oxazin-1-one

Participants

Reaction Conditions

Reaction Steps

In a 10 ml microwave vial was 6-bromo-7-phenyl-1H-pyrido[2,3-b][1,4]oxazine-2(3H)-thione (1 g, 3.11 mmol) and ethylhydrazine carboxylate (1.2 g, 12.44 mmol) in p-xylene (10 ml) to give a yellow suspension. The reaction mixture was heated to 180° C. for 45 minutes under microwave conditions. The crude residue was concentrated under reduced pressure and purified by Biotage silica gel chromatography (gradient 0% to 100% ethyl acetate in n-hexane) to give the title compound (293 mg, 27%). LCMS (Method D) RT 1.069 min, M+1=346.

Provenance & Evidence