Isatin derivatives have important biological and pharmacological properties. In particular, ketals of 5-haloisatin exhibit anticonvulsant'and ansiolitic2 activities. The classical method to prepare isatins first reported by Sandme~ er,~.~ requires several reagents and may produce hydrogen cyanide as a by-product? and the yields vary between 70 to 85%. 5-Chloroisatin and 5-bromoisatin can also be prepared from isatin using chlorine or bromine respectively ...
