Synthesis, NMR, X-ray crystallography and DFT studies of some regioisomers possessing imidazole heterocycles

PÜSKÜLLÜ M. O., Doganc F., Ozden S., ŞAHİN E., ÇELİK İ., Goker H.

JOURNAL OF MOLECULAR STRUCTURE, cilt.1243, 2021 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 1243
  • Basım Tarihi: 2021
  • Doi Numarası: 10.1016/j.molstruc.2021.130811
  • Dergi Adı: JOURNAL OF MOLECULAR STRUCTURE
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Chemical Abstracts Core, INSPEC
  • Anahtar Kelimeler: Imidazo[4,5-b]pyridine, Imidazo[4,5-d]pyrimidine, Regioisomer, NOESY, H-1-N-15 HMBC, DFT, HMBC NMR, DIFFERENTIATION, ELUCIDATION
  • Atatürk Üniversitesi Adresli: Evet

Özet

Imidazole-containing heterocycles: Imidazopyridines, imidazopyrimidines can exist in several tautomeric forms. Their regioselectivities were determined for N-alkylations with 4-chlorobenzyl bromide under basic conditions (K2CO3) in DMF. We observed that, regioisomers were mainly formed as a mixture in this reaction and N-benzylation occurs at a higher ratio on six membered heterocycles. Their structural assignments were made with the use of two-dimensional H-1-H-1 NOE (Nuclear Overhauser Effect Spectroscopy, NOESY) and H-1-N-15 HMBC (Heteronuclear Multiple Bond Correlation) spectra. Further confirmation of the structure of 2c and 3c were obtained from X-ray crystallography. Experimental data was confirmed by Density Functional Theory (DFT) studies as well. (C) 2021 Elsevier B.V. All rights reserved.