USE OF THIAZYL CHLORIDES, ALKYL CARBAMATES, AND THIONYL CHLORIDE TO FUSE 1,2,5-THIADIAZOLES TO QUINONES AND TO OXIDIZE, CHLORINATE, AND AMINATE THEM

Thiazyl chlorides in a simple one-step procedure fuse 1,2,5-thiadiazol e rings to quinones. So do alkyl carbamates mixed with excess thionyl chloride and pyridine. Evidence is put forward to support the hypothes is that NSCl or a related thiazyl derivative is the reactive species t hat brings about the transformations. Selenoyl chloride mixed with an alkyl carbamate, pyridine, and quinones similarly gives 1,2,5-selenodi azoloquinones. Thionyl chloride in pyridine chlorinates quinones and o xidizes hydroquinones. 2,3-Dichloro-1,4-quinones with S4N4 or. with al kyl N-sulfinylcarbamates give 1,2,5-thiadiazoloquinones. Quinones and their 2 3-dichloro derivatives with TsNSO in pyridine give betaine der ivatives of 2,3-diaminoquinones, which pyrrolidine converts into 2-ami no-3(tosylamino)quinones. A unified set of mechanisms is presented tha t accounts for these transformations.