Synthesis and properties of 2-benzylidene-8,9-dihydro-7H-furo[2,3-f][1,3]benzoxazin-3(2H)-one derivatives

Aminomethylation of 6-hydroxyaurones with primary amines was used to synthesize 2-benzylidene-8,9-dihydro-7H-furo[2,3-f][1,3]-benzoxazin-3(2H)-one derivatives, while opening of 1,3-oxazine ring in the presence of acid gave secondary amines containing a 6-hydroxyaurone moiety. Acetylation of 2-benzylidene-8,9-dihydro-7H-furo[2,3-f][1,3]benzoxazin-3(2H)-ones was also accompanied by opening of 1,3-oxazine ring.