Synthesis of Tetraaminoalkenes containing the Reduced Pyrimidine Skeleton and the X-ray Molecular Structure of 1,1′-Ethylene-3,3′-dibenzylbi(hexahydropyrimidin-2-ylidene)

Abstract

Deprotonation of a 1,1′-bridged bis(1,3-dialkyl-1,4,5,6-tetrahydropyrimidinium) diiodide with NaH gives in high yield a tetraaminoalkene 4, whereas the corresponding non-bridged tetrahydropyrimidinium iodide reacts with NaH only in the presence of KOBut; the title bridged tetraaminoalkene 4f was structurally characterized by single-crystal X-ray diffraction.