Green Chemistry Letters and Reviews (Apr 2020)

Efficient eco-friendly syntheses of dithiocarbazates and thiosemicarbazones

  • Nur Halilatul Sadiqin O. Ali,
  • Malai Haniti S. A. Hamid,
  • Nurul Amirah ‘Aqilah Mohamad ‘Asri Putra,
  • Hajar Azirah Adol,
  • Aminul Huq Mirza,
  • Anwar Usman,
  • Tasneem A. Siddiquee,
  • Md. Rejaul Hoq,
  • Mohammad R. Karim

DOI
https://doi.org/10.1080/17518253.2020.1737252
Journal volume & issue
Vol. 13, no. 2
pp. 129 – 140

Abstract

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Eight Schiff bases have been synthesized by conventional and three different eco-friendly methods, whereby two aromatic carbonyl compounds viz. 2-thiophenecarboxaldehyde and salicylaldehyde were reacted with S-methyl, S-benzyl, and S-n-octyl-dithiocarbazates and thiosemicarbazide. In order to evaluate the efficiency of the synthesis methods, the time to complete the reaction and the yield of the Schiff base synthezised by eco-friendly methods, such as solvent-free grinding, water as a solvent, and lemon juice as catalyst, were compared with those synthesized by the conventional method. The chemical structures of all the synthesized Schiff bases, where two of them are novel and reported for the first time, were fully characterized by a variety of physico-chemical, analytical, and spectroscopic techniques. The molecular and crystal structures of the Schiff bases especially those having 2-thiophene moiety were further elucidated by single crystal X-ray diffraction analyzes.

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