Tetramethylmesoxalamide and Tetramethyl-1,3-Dithiomesoxalamide

Abstract

The chemistry of mesoxalic acid derivatives was investigated many years ago.² For example, Curtiss demonstrated that dimethyl mesoxalate added ethanol to produce a stable isolatable hemiketal,³ whereas the corresponding diethyl ester presumably gave the ethyl hemiketal at −15°, but it could not be isolated.⁴ These esters are readily hydrated, and strongly dehydrating conditions are required to regain the ketone.⁵ Guyot and Esteva⁶ condensed mesoxalic esters with aromatic compounds in sulfuric acid to produce the corresponding α-hydroxyarylmalonates and diaryl-malonates. Curtiss^3,4 showed that aromatic amines condensed with ethyl mesoxalate to produce carbonyl adducts (Schiffs bases, hydroxyamines), while Heinisch⁷ showed that aliphatic amines produced 2-hydroxy-2-alkylamino-N,N′-dialkylmalonamides. Other derivatives, such as mesoxalonitrile,⁸ and several different amides^7,9 have been reported. Brudnoy¹⁰ reported an unusual imidazole on treatment of diethyl mesoxalate with ammonia, although earlier reports^7,9 showed that the hydrate, 2,2-dihydroxymalonamide, was obtained in good yield in this reaction.