Reactions of 4-methoxy-3-quinolinyl and 1,4-dihydro-4-oxo-3-quinolinyl sulfides aiming at the synthesis of 4-chloro-3-quinolinyl sulfides [1]

Article abstract of DOI:10.1002/jhet.5570300627

The preparation of 1,4-dihydro-4-oxo-3'-alkylthio-3,4'-diquinolinyl sulfides 3 or 1,4-dihydro-4-oxo-3-(alkylthio)quinolines 4 by acid catalysed hydrolysis of 4-methoxy-3'-alkylthio-3,4'-diquinolinyl sulfides 1 or 4- methoxy-3-(alkylthio)-quinolines 2 is described. The reactions of 4-methoxy- 3'-alkylthio-3,4'-diquinolinyl sulfides 1 or 1,4-dihydro-4-oxo-3'-alkylthio- 3,4'-diquinolinyl sulfides 3 with phosphoryl chloride in DMF afforded 4- chloro-3'-alkylthio-3,4'-diquinolinyl sulfides 5. Treatment of the title compounds 1 or 3 with boiling phosphoryl chloride systems: leads to 4- chloro-3-(alkylthio)quinolines 6 and thioquinanthrene but those of alkoxy- or oxo-quinolines 2 or 4 lead to 4-chloro-3-(alkylthio)quinolines 6. The reactions of N-methyl-4(1H)-quinolinones 3n and 4n with phosphoryl chloride directed to 4-chloro-3-(alkylthio)quinolines 6 were studied as well.