Document Type: Research Note
Department of Chemistry, Faculty of Science, Teacher Training University, Tehran, I.R. IRAN
The cyclization of b-anilino propionic acids in the presence of polyphosphoric acid (PPA) afforded the 2,3-Dihydroquinoline-4-(1H)-ones in good yields. N,N'-bis(2-carboxyethyl)-4-methyl-1,2-diaminobenzene (7) is cyclized under this condition to produce the 1,5-diaza-2,3,6,7-tetrahydro-4-methyl-pheranthrene-4,8-dione(bis-quinolone) (8).