76097-80-8Relevant academic research and scientific papers
Heterocycles from Substituted Amides. VIII (1,2). Oxazole derivatives from Reaction of Isocyanates with 2-Isocyanoacetamides
Chupp, John P.,Leschinsky, Kindrick L.
, p. 711 - 715 (2007/10/02)
A facile reaction of 2-isocyanoacetamides 1 with reactive aryl and sulfonyl isocyanates is shown to give 5-amino-2-oxazolecarboxamides 3 in a reaction arising from electrophilic attack of isocyanate with the nucleophilic isocyanide carbon.This reaction, perhaps proceeding through an unstable nitrile ylid intermediate reminiscent of the Cornforth rearrangement, is a first example of ring closure via acylation, involving the activated methylene of an organic isocyanide, without recourse to added base.Isomeric 5-amino-4-oxazolecarboxamides 4 are formed when 5-aminooxazoles 2 react with isocyanates.Since 2 has previously been shown to easily form by thermal isomerization of 1, methods exist for the preparation of both 5-amino- 2- and 4-oxazolecarboxamides from the single starting material 1.In contrast, 1 with acyl isocyanates is shown to give a variety of products, including iminooxazolinediones, 5-amino-2-oxazolecarboxamide 3 and 2(1) pyrazinones (tentatively identified), depending on the structure of the isocyanates.
