Synthesis and Reactions of 4H-Imidazo(4,5-e)(2,1,3)benzothiadiazol-5( 6H)-one.-The condensation of the diamino benzothiadiazole (I) with urea provides the imidazo derivative (III). Some reactions such as oximation and dialkylation are investigated. Corresponding monosubstituted derivatives of type (XI) are prepared via independently produced isoprenyl derivatives. -(RAO, D. M.; GIRIDHAR, T.; PRASAD, G. V.; REDDY, R. B.; CHANDRA MOULI, G. V. P.; Heterocycles 45 (1997) 1, 19-28; Res. Dev. Cent., Cheminor