Studies in the quaternisation of 2,1,3-benzothiadiazole and 2,1,3-benzoselenadiazole. Part II. The preparation of higher alkyl quaternary salts

Abstract

Both 2,1,3-benzothiadiazole and 2,1,3-benzoselenadiazole undergo quaternisation satisfactorily with n-propyl, n-butyl, and n-pentyl 2,4-dinitrobenzenesulphonates; the compounds obtained are further characterised by conversion to the quaternary iodides. Thermal instability of isoalkyl esters of 2,4-dinitrobenzenesulphonic acid makes the preparation of quaternary salts with these difficult, but not impossible. A s-alkyl quaternary compound of 2,1,3-benzoselenadiazole (isopropyl-2,1,3-benzoselenadiazolium iodide) is described.