3′-Methylsulfinyl-3,4′-diquinolinyl sulfides

Reactions of 4-methoxy- or 1,4-dihydro-4-oxo-3′-methylthio-3,4′-diquinolinyl sulfides 1 and 7 with a nitrating mixture ran as the 3′-methylthio group 5-mono-oxidation followed by C₆- and C₈-nitration and led to the mixture composed of products 3, 4, 5 and 6 (in the case of substrate 1 ) or compounds 5 and 6 (for substrate 7 ). In the reaction with hydrochloric acid 4-methoxy-3′-methylsulfinyl-3,4′-diquinolinyl sulfides 3 and 4 could be hydrolysed to 3′-methylsulfinyl-4(1H)-quinolinones 5 or 6 respectively, the methylsulfinyl group remaining unaffected.