Decoding the reaction mechanism of the cyclocondensation of ethyl acetate2-oxo-2-(4-oxo-4H-pyrido [1.2-a] pyrimidin-3-yl) polyazaheterocycle and ethylenediamine using bond evolution theory

Mbah Bake Maraf; Adjieufack Abel Idrice; Manwal A Mekoung Pélagie; Auguste Abouem A Zintchem; Gouet Bebga; Lydia Rhyman; Mbouombouo Ndassa Ibrahim; Ponnadurai Ramasami

doi:10.1002/jcc.26853

Decoding the reaction mechanism of the cyclocondensation of ethyl acetate2-oxo-2-(4-oxo-4H-pyrido [1.2-a] pyrimidin-3-yl) polyazaheterocycle and ethylenediamine using bond evolution theory

J Comput Chem. 2022 May 30;43(14):972-985. doi: 10.1002/jcc.26853. Epub 2022 Apr 5.

Authors

Mbah Bake Maraf^{1

2}, Adjieufack Abel Idrice^{1

2

3}, Manwal A Mekoung Pélagie^{1

2}, Auguste Abouem A Zintchem², Gouet Bebga², Lydia Rhyman^{4

5}, Mbouombouo Ndassa Ibrahim², Ponnadurai Ramasami^{4

5}

Affiliations

¹ Physical and Theoretical Chemistry unit, Laboratory of applied Physical and Analytical Chemistry, Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon.
² Computational Chemistry Laboratory, Department of Chemistry, Higher Teacher Training College, University of Yaoundé I, Yaoundé, Cameroon.
³ Laboratory of Theoretical Chemistry (LCT) and Namur Institute of Structured Matter (NISM), University of Namur, Namur, Belgium.
⁴ Computational Chemistry Group, Department of Chemistry, Faculty of Science, University of Mauritius, Réduit, Mauritius.
⁵ Centre for Natural Product Research, Department of Chemical Sciences, University of Johannesburg, Doornfontein, South Africa.

PMID: 35383996
DOI: 10.1002/jcc.26853

Abstract

We investigated the flow of electron density along the cyclocondensation reaction between ethyl acetate 2-oxo-2-(4-oxo-4H-pyrido[1.2-a]pyrimidin-3-yl) polyazaheterocycle (1) and ethylenediamine (2) at the ωB97XD/6-311++G(d,p)computational method within of bond evolution theory (BET). The exploration of potential energy surface shows that this reaction has three channels (1-3) with the formation of product 3 via channel-2 (the most favorable one) as the main product and this is in good agreement with experimental observations. The BET analysis allows identifying unambiguously the main chemical events happening along channel-2. The mechanism along first step (TS2-a) is described by a series of four structural stability domains (SSDs), while five SSDs for the last two steps (TS2-b and TS2-c). The first and third steps can be summarized as follows, the formation of N1-C6 bond (SSD-II), then, the restoration of the nitrogen N1 lone pair (SSD-III), and finally, the formation of the last O1-H1 bond (SSD-IV). For the second step, the formation of hydroxide ion is noted, as a result of the disappearance of V(C6,O7) basin and the transformation of C6-N1 single bond into double one (SSD-IV). Finally, the appearance of V(O7,H2) basin lead to the elimination of water molecule within the last domain is observed.

Keywords: catastrophe theory; cyclocondensation reaction; electron localization function; polyazaheterocycle compounds; reaction mechanism.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.
Research Support, Non-U.S. Gov't

MeSH terms

Ethylenediamines*
Nitrogen*
Water

Substances

Ethylenediamines
Water
Nitrogen