A FACILE ONE-POT SYNTHESIS OF MODEL DIETHYL 6,6'-DIOXOTETRAHYDRO-5,5'-BI(1,2,4-TRIAZINE)-5,5'-DICARBOXYLATES

摘要

The reaction of diethyl aminomalonate with nitrile imine 1,3-dipolar species 1a,b follows a stereospecific path to deliver the racemic tetrahydro-6,6'-dioxo-5,5'-bi(1,2,4-triazine)-5,5'-dicarboxylates 4a,b, whilst the corresponding diastereomeric meso forms (5R, 5'S) could not be detected in the reaction product. Structural assignments for these novel heterocyclic dimers are based on microanalytical and spectral (MS, NMR) data, and further confirmed by X-ray diffraction analysis of single crystal for 4a.