The Oxygenation of 2-Oxazolin-5-ones: A New Synthesis of Imides

Abstract

In the presence of mild base such as triethylamine, the two 4-alkylidene-2-phenyI-2-oxazolin-5-ones, 1 and 8, rapidly absorb oxygen at room temperature with the loss of carbon dioxide and the formation of the imides 4 and 10. The imide probably arises by decomposition of a hydroperoxide resulting from the reaction of oxygen and the anion of the oxazolinone. A hydroperoxide intermediate will also account for the origin of the acidic by-products 6 a and l l a . The 2-methyl-2-oxazolin-5-one 14 did not react with oxygen at room temperature; at 60" some reaction occurred but no imide was formed.Lorsque mis en presence d'une base faible comme la triethylamine, les deux alkylidkne-4 phenyl-2 oxazolin-5-ones, I et 8 absorbent rapidement de I'oxygkne a la temperature ambiante pour ensuite liberer du gaz carbonique et conduire aux imides 4 et 10. La formation d'un imide peut &tre attribuee a la decomposition d'un hydroperoxyde issu de la reaction entre I'oxygtne et I'anion de I'oxazolinone. L'intermediaire hydroperoxyde peut aussi expliquer I'origine des produits secondaires acidiques Q et llcr. La methyl-2-oxazolin-5-one 14 ne reagit pas avec I'oxygine a la temperature ambiante: toutefois a 60" une transformation fut observee mais non la formation d'un imide.

Synthesis and properties of the .alpha.-keto acids

“…70-75% yield.362 Fissekis et al have shown that cycloalkylglyoxylic acids (C6 and C5 rings) readily react with 4,5,6-triaminopyrimidine(225) in strong acid to yield 4amino-6-cycloalkyl-7-hydroxypteridines(226a,b)…”