aminocarboxylic acidsaminocarboxylic acids (hydrazinocarboxylic acids) and esters (acyclic compounds) P 0270
-084Exotic Amino Acids.Part 4. Synthesis of Methyl Esters of Some N-Heteroaminomethylenemalonic Acids.-Isopropylidene N-hetarylaminomethylenemalonates (III), obtained from the corresponding ethoxymethylenemalonates (I) and amino-substituted heterocycles (II), undergo methanolysis to give the corresponding N-hetarylaminomalonates (V). N-hetarylaminomethylenemalonate, containing a 2-aminothiazole group as a heterocyclic substituent, does not react under analogous conditions, but cyclizes upon heating to give thiazolopyrimidinecarboxylic acid (VI). 4-Oxopyridinopyrimidines (VII) are obtained upon sublimation of compounds (III). -(ZICANE, D.; RAVINYA, I.; TETERE, Z.; RIJKURE, I.; GUDRINIECE, E.; KALEJS, U.; Chem. Heterocycl.