Arenediazothioalkanoic (Arylazothioalkanoic) acids by coupling of arenediazonium compounds with 2-Mercaptoalkanoic acids

GRAPHICAL ABSTRACT

ABSTRACT

The title compounds – arenediazothioethanoic acids and 2-arenediazothiopropanoic acids – have been synthesized by the coupling of arenediazonium phosphates with 2-mercaptoacetic or 2-mercaptopropanoic acid in aqueous media at pH ∼ 4. Included are hitherto unreported benzenediazothioethanoic acid and 2-benzenediazothiopropanoic acid prepared in pure form, as well as a number of mostly para ring-substituted examples. Mass spectral fragmentation patterns of selected title compounds are discussed, along with a brief preliminary account of their Z/E-isomerization and thermal stabilities.

KEYWORDS:

• Diazo coupling
• thiols
• EIMS fragmentation
• Z/E-isomerization
• thermal stability