~1H NMR SULFINYL GROUP SUBSTITUENT EFFECTS OF DITHIINODIAZINE S-OXIDES AS A KEY FOR STRUCTURE ASSIGNMENT OF PARENT DITHTINODIAZINES

摘要

1,4-Dithiinodipyridine 1 was prepared by reduction of 4-chloro-3-chlorosulfonylopyridine(8)with HI / H3PO3 system.Sulfur-assisted thermal isomerization of 1 resulted in a mixture of 1 and 2.Treatment of dithiinodiazines 1,2,5,and 6 with a nitrating mixture led almost selectively to respective S-monooxides 1a,2a,5a,and 6a.Due to the significant values of sulfinyl group substituent effects,~1H NMR spectra of 1,4-dithiino-S-oxides 1a,2a,5a,and 6a permitted for structure assignment of parent dithiins 1,2,5,and 6 and confirmed regioselectivity of the reaction of dithiins 1,2,5,and 6 with nitrating mixture.