Crystal structure and spectral characteristics of 2-methyl-3-chloro-9- hydroxypyrido[1,2-a]pyrimidin-4-one and bis(2-methyl-3-chloro-9-hydroxypyrido[1, 2-a]pyrimidin-4-onium) perchlorate

- 2-Methyl-3-chloro-9-hydroxypyrido[1,2-a]pyrimidin-4-one (I) and bis(2-methyl-3-chloro-9-hydroxypyrido[1,2-a]pyrimidin-4-onium) perchlorate (Ia) are synthesized and studied by X-ray diffraction and IR spectroscopy. It is shown that compound I exists in the molecular form in crystals and in the zwitterion form in solutions. The structural units of compound Ia are partially protonated centrosymmetric dimeric cations and perchlorate anions. The dimeric cation involves two molecules I in the zwitterion form. These molecules are linked together by a strong symmetric hydrogen bond formed with the participation of a proton located at the inversion center. The structures of a series of pyrido[1,2-a]pyrimidines are investigated and compared. It is demonstrated that the tautomeric equilibrium revealed in solutions of compounds of this class depends on the solvent type and pH of the medium. © 2004 MAIK "Nauka/Interperiodica".

Authors
Koval'chukova O.V. 1 , Mordovina N.I. 1 , Kuz'mina N.E.2 , Nikitin S.V. 3 , Zaǐtsev B.E. 1 , Strashnova S.B. 1 , Palkina K.K.2
Editors
-
Publisher
-
Number of issue
5
Language
English
Pages
792-797
Status
Published
Department
-
Number
-
Volume
49
Year
2004
Organizations
  • 1 Peoples' Friendship University, ul. Miklukho-Maklaya 6, Moscow, 117197, Russian Federation
  • 2 Kurnakov Inst. Gen. and Inorg. Chem., Russian Academy of Sciences, Leninskiǐ pr. 31, Moscow, 119991, Russian Federation
  • 3 Research Institute of Pharmacology, Russian Academy of Medical Sciences, Moscow, Russian Federation
Keywords
2 methyl 3 chloro 9 hydroxypyrido[1,2 a]pyrimidin 4 one; ampholyte; bis(2 methyl 3 chloro 9 hydroxypyrido[1,2 a]pyrimidin 4 onium)perchlorate; cation; dimer; perchlorate; solvent; unclassified drug; article; crystal structure; hydrogen bond; infrared radiation; molecule; pH; proton transport; spectroscopy; structure activity relation; synthesis; X ray diffraction
Date of creation
19.10.2018
Date of change
19.10.2018
Short link
https://repository.rudn.ru/en/records/article/record/3603/