Synthesis of thiadiazolo-<i>s</i>-triazines for their antiviral activity based on QSAR studies

Abstract

2-Amino-5-aralkyl-1,3,4-thiadiazole <b>1</b> on treatment with benzaldehyde yields 5-aralkyl-2-benzylideno-imino-1,3,4-thiadiazole <b>2</b> which on reaction with ammonium thiocyanate cyclises to give 2-phenyl-7-aralkyl-1 ,3,4-thiadiazolo-[3,2-<i>a</i>]-<i>s</i>-triazine-5- [6<i>H</i>,7 <i>H</i>]-thione <b>3</b>. Reaction of <b>3</b> with <i>p</i>-toluene sulphonyl chloride in anhydrous chloroform gives 2-phenyl-3-(<i>p</i>-toluenesulphonyl)-7-aralkyl-1,3,4-thiadiazolo-[3,2-<i>a</i>]-<i>s</i>-triazine-5-[6<i>H</i>, 7<i>H</i>]-thiones <b>4g-1</b>. Benzoyl chloride also reacts with <b>3</b> in anhydrous pyridine giving 2-phenyl-3-(benzoyl)-7-aralkyl-1,3,4-thiadiazolo-[3,2-<i>a</i>]-<i>s</i>-triazine-5-[6<i>H</i>,7 <i>H</i>]-thiones <b>4a-f</b> in quantitative yields. The antiviral activities of <b>4</b> based on QSAR studies have been reported using physicochemical method.