Synthesis of biologically active thiazolo-benzopyranyl-<i>s</i>-triazine derivatives

Abstract

6<i>-</i>Amino-2-oxo-2<i>H</i> [1]-benzopyran on oxidative cyclisation with potassium thiaocynate, acetic acid and bromine at 0-5°C gives 2-amino<i>-</i>7<i>H </i>[6]- thiazolo [5,4-<i>d</i>] benzopyran-7-one <b>1</b>, which on treatment with cyanuric chloride in alcohol gives 2-(2'-amino-7'-oxo-7' <i>H </i>[6']- thiazolo [5', 4'-<i>d</i>] benzopyranyl)-4-6-dichloro-<i>s</i>-triazine <b>2</b>. 6-Amino-2-oxo-2<i>H </i>[1]-benzopyran on refluxing with ammonium thiocynate in hydrochloric acid and ethanol gives 6-thioureido-2<i>H</i> [1]-benzopyran-2-one <b>3</b>. Compound <b>2</b> on refluxing with <b>3</b> in alcohol gives 2-(2'-amino-7'-oxo-7'<i>H </i>[6']- thiazolo [5', 4'-<i>d</i>] benzopyranyl)-4-(6"thioureido-2" <i>H-</i>[1<i>"</i>]-2<i>"</i> -oxo-benzopyranyl)-6-chloro-<i>s</i>-triazine <b>4</b>. The similar reaction is repeated on <b>4</b> to give 2-(2'-amino-7' -oxo-7' <i>H </i>[6']- thiazolo [5', 4'-<i>d</i>] benzopyranyl)-4-(6<i>"</i>-thioureido-2" <i>H </i>[1<i>"</i>]-2<i>"</i>-oxo benzopyranyl)-6-(6<i>'" </i>-thioureido-2<i>'"</i> <i>H</i>[1<i>"'</i>]-2<i>'"</i> -oxo-benzopyranyl)-<i>s</i>-triazine <b>5</b>. The structures of all compounds are confirmed on the basis of analytical and spectral data. Some of the compounds show significant antibacterial activity.