Synthesis of pyrimidines, aromatic and heteroaromatic acids as Biginelli reaction catalysts

Aromatic as well as heteroaromatic acids were found to beexcellent catalysts for the Biginelli three component synthesisof dihydropyrimidinones. Benzoic acid, substituted benzoic acids, five- and six- membered heterocyclic acids can be used for this purpose

A vibrational study of di-i-propoxyphosphoryl benzylisothiourea

17 p. : il.The Fourier transform infrared and Raman spectra of di-i-propoxyphosphoryl benzylisothiourea (DPB) (1) in the solid state and in solutions of CCl4, CHCl3, CHBr3, CH2Cl2, C2H4Cl2, C2H4Br2 and THF were studied. In the IR spectra, the effects of different concentrations were also investigated. The behavior of the n(NH), d(NH), d(HNH), n(C N) and n(P O) normal modes suggests the existence of a tautomerism between the phosphorylamine (I) and N-phosphorylimine (II) structures: The data show the presence of different d(NH) and d(HNH) bendings and n(C N) normal modes in the solid state as a result of inter and intramolecular hydrogen bonding. The experimental approximate frequencies assignments were done for this compound, and were confirmed by a normal coordinate analysis carried out for several fragments of phosphorylamine and N-phosphorylimine structures