Hemi-synthesis of novel chiral benzodiazepine derivatives from Eucalyptus citriodora essential oil: 2D NMR experiments and differential scanning calorimetry study of diastereoisomers

Brahim Cherfaoui; Farid Chebrouk; Ridha Hassaine; Massaab Khalfaoui; Leϊla Boukennna; Mohammed Salah Eddine Hamroun; Mohamed Abou-Mustapha; Gacem Lazhar

doi:10.1080/14786419.2023.2185888

Hemi-synthesis of novel chiral benzodiazepine derivatives from Eucalyptus citriodora essential oil: 2D NMR experiments and differential scanning calorimetry study of diastereoisomers

Nat Prod Res. 2023 Mar 8:1-12. doi: 10.1080/14786419.2023.2185888. Online ahead of print.

Authors

Brahim Cherfaoui^{1

2}, Farid Chebrouk^{1

3}, Ridha Hassaine^{1

4}, Massaab Khalfaoui², Leϊla Boukennna^{1

2}, Mohammed Salah Eddine Hamroun¹, Mohamed Abou-Mustapha¹, Gacem Lazhar¹

Affiliations

¹ Scientific and Technical Center of Research in Physical and Chemical Analysis CRAPC, BP384, Tipaza, Algeria.
² Laboratory of Polymeric Materials (LPM), Faculty of Chemistry, U.S.T.H.B., Algiers, Algeria.
³ Laboratory of Biomathematics, Biochemistry, Biophysics and Scientometrics (L3BS), Faculty of Nature and Life Sciences (FSNV), University of Bejaia, Bejaia, Algeria.
⁴ Laboratory of Catalysis and Synthesis in Organic Chemistry, Faculty of Sciences, University of Tlemcen, Tlemcen, Algeria.

PMID: 36890766
DOI: 10.1080/14786419.2023.2185888

Abstract

An efficient in situ condensation of citronellal, the main constituent of Eucalyptus citriodora essential oil (51%), with different amine derivatives of 2,3-diaminomaleonitrile and 3-[(2-aminoaryl)amino]dimedone has led to novel chiral benzodiazepine structures. All reactions were precipitated in ethanol and pure products were obtained in good yields (58-75%) without any purification. The synthesized benezodiazepines were characterized by spectroscopic techniques, namely ¹H-NMR, ¹³C-NMR, 2D NMR and FTIR. Differential Scanning Calorimetry (DSC) and HPLC were used to confirm the formation diastereomeric mixtures of benzodiazepine derivatives.

Keywords: Eucalyptus citriodora; Hemi-synthesis; benzodiazepines; differential scanning calorimetry; essential oil.