Synthesis of 4-Oxo-3,4-dihydro-1H-thieno- and thienothiadiazine 2,2-Dioxides
4-Oxo-3,4-dihydro-1H-thienothiadiazine 2,2-dioxide (3) has been synthesized in a two-step approach involving sulfamoylation of 3-amino-4-methoxycarbonylthiophene (1) and subsequent ring closure.A modification of this procedure, which involve