Chemistry of isatin. Synthesis of 2,3-diketo-1H-pyrol[2,3-b]-dibenzo-p-dioxin

2-Acetyldibenzo-p-dioxin was prepared (similar to 50% yield) by reaction of dibenzo-p-dioxin with acetyl chloride and titanium (IV) chloride. Starting from 2-aminodibenzo-p-dioxin some new isatin derivatives were obtained usi ng Sandmeyer reaction. The newly synthesised compounds were characterised b y IR, NMR spectra and elemental analysis.