HYDROGEN-SULFIDE SPLITTING OF N,N'-DIMETHYL BIS-SALTS OF THIOQUINANTHRENE AND ISOTHIOQUINANTHRENE

The reactions of bis-salts of N,N'-dimethyl-1,4-dithiino[beta-gamma':b eta'-gamma or beta-beta':gamma-gamma']diquinolines 3 or 5 with hydroge n sulfide proceeded with breaking the gamma-quinolinyl-sulfur bond lea ving beta-one unaffected and led to aqueous alkali soluble mercapto-th iones 4 or aqueous alkali insoluble dithione 6. It allows for the simp le distinction between isomeric dithiinodiquinolines such as 1 and 2. Sulfur assisted thermal isomerization of compound 1 to 2 and vice-vers a was also described. H-1 NMR assignment of compounds with 1-methyl-3, 4-disubstituted quinoline fragment was presented.