Glucose:urea:NH₄Cl low melting mixture for the synthesis of symmetric azines

Abstract

Alternate reaction media have become very important due to the problems created by the highly volatile nature of the solvents. The deep eutectic mixture is a kind of an alternate reaction medium which has emerged in recent years. Low melting mixtures were introduced by making the deep eutectic mixture more cost-effective and renewable by introducing carbohydrates into it. The properties of low melting mixtures include easiness to prepare, usage of low-cost components, biodegradability, solubility in water, easy separation from organic compounds, etc. The low melting mixtures such as glucose:urea:NH₄Cl, glucose:ChCl, glucose:urea:ChCl, glycerol:urea:NH₄Cl, and ethylene glycol:urea:NH₄Cl were used in different ratios for the reactions. The properties such as viscosity, density, acidity, glass transition temperature, and thermal stability were studied. An unusual method for the synthesis of symmetrical azines is introduced wherein benzaldehyde and hydroxylamine are reacted in the presence of glucose:urea:NH₄Cl. The method of synthesis needs only less reaction time, temperature and the product was easily separated. The products were confirmed using GC-MS and NMR techniques. The recyclability of glucose:urea:NH₄Cl was studied.

GRAPHICAL ABSTRACT

KEYWORDS:

• Catalysis
• deep eutectic mixtures
• green chemistry
• low melting mixtures
• symmetric azines

Additional information

Funding

The authors thank Cochin University of Science and Technology for the financial support