Unusual formation of (E)-11-(amino-methyl-ene)-8,9,10,11-tetra-hydro-pyrido[2',3':4,5]pyrimido[1,2- a]azepin-5(7 H)-one and its crystal structure

Khamid U Khodjaniyazov; Utkir S Makhmudov; Kambarali K Turgunov; Burkhon Z Elmuradov

doi:10.1107/S2056989017013093

Unusual formation of (E)-11-(amino-methyl-ene)-8,9,10,11-tetra-hydro-pyrido[2',3':4,5]pyrimido[1,2- a]azepin-5(7 H)-one and its crystal structure

Acta Crystallogr E Crystallogr Commun. 2017 Sep 19;73(Pt 10):1497-1500. doi: 10.1107/S2056989017013093. eCollection 2017 Oct 1.

Authors

Khamid U Khodjaniyazov¹, Utkir S Makhmudov¹, Kambarali K Turgunov¹, Burkhon Z Elmuradov¹

Affiliation

¹ S.Yunusov Institute of the Chemistry of Plant Substances Academy of Sciences of, Uzbekistan Mirzo Ulugbek Str., 77, Tashkent 100170, Uzbekistan.

Abstract

Selective C-formyl-ation of 8,9,10,11-tetra-hydro-pyrido[2',3':4,5]pyrimido[1,2-a]-azepin-5(7H)-one has been studied for the first time. It was revealed that formyl-ation proceeds by the formation of an inter-mediate salt, which due to the re-amination process on treatment with aqueous ammonia transformed into the corresponding (E)-11-(amino-methyl-ene)-8,9,10,11-tetra-hydro-pyrido[2',3':4,5]-pyrimido[1,2-a]azepin-5(7H)-one, C₁₃H₁₄N₄O, as an E-isomer. Formyl-ation was carried out by Vilsmeier-Haack reagent and the structure of the synthesized compound was confirmed by X-ray structural analysis, spectroscopic and LC-MS methods. In the mol-ecule, the seven-membered penta-methyl-ene ring adopts a twist-boat conformation.

Keywords: Vilsmeier–Haack reagent; X-ray structure analysis; crystal structure; formylation; fused pyrimidines.

Grants and funding

This work was funded by Academy of Sciences Republic of Uzbekistan grant FA-F7-T207.