General Papers ARKIVOC 2011 (xi) 69-81 Synthesis of [1,3,2]dithiazolo[4,5-b][1,2,5]oxadiazolo[3,4-e]pyrazines Lidia S. Konstantinova,a Vadim V. Popov,a Natalia V. Obruchnikova,a Konstantin A. Lyssenko,b Ivan V. Ananyev,b and Oleg A. Rakitina* aN. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect, 47, 119991 Moscow, Russia bA. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov Str., 28, 119991 Moscow, Russia E-mail:
[email protected] Abstract The reaction temperature has a strong impact on the results of chlorination of 5,6-bis(tert- butylthio)[1,2,5]oxadiazolo[3,4-b]pyrazine that is readily prepared from 5,6- dichloro[1,2,5]oxadiazolo[3,4-b]pyrazine and sodium tert-butylsulfide. Mono- and bis(sulfenylchlorides) were selectively obtained in high yield and their structure was confirmed by the reaction with morpholine. Treatment of [1,2,5]oxadiazolo[3,4-b]pyrazine-5,6-disulfenyl dichloride with primary aliphatic amines and benzylamine afforded N-substituted [1,3,2]dithiazolo[4,5-b][1,2,5]oxadiazolo[3,4-e]pyrazines in moderate yields. Novel pentacyclic [1,2,5]oxadiazolo[3'',4'':5',6']pyrazino[2',3':5,6][1,2,4]thiadiazino[3,4-b][1,3]benzothiazole, whose structure was confirmed by X-ray diffraction, was obtained by the reaction of this disulfenyl dichloride with 2-aminobenzothiazole. Keywords: Fused 1,3,2-dithiazoles, [1,2,5]oxadiazolo[3,4-b]pyrazines, disulfenyl dichlorides, primary amines, bis(tert-butylthio) derivatives, chlorination Introduction Amongst five-membered