Md. Bianco et al., (o-Trifluoroacetamido)cinnamaldehyde dimethylhydrazone, a useful azadiene in the hetero Diels-Alder approach to the pyrido[2,3,4-kl]acridine system, SYNLETT, (5), 2000, pp. 689-691
The hetero Diels-Alder reaction between (o-trifluoroacetamido)cinnamaldehyd
e dimethylhydrazone and several quinones followed by aromatization and hydr
olytic cyclization afforded the corresponding pyrido[2,3,4-kl]acridine deri
vatives in 26-43% overall yields.