Microwave Assisted Synthesis of Schiff Bases: A Green Approach

Abstract

In the present study Schiff’s bases are synthesized by the conventional as well as by microwave irradiation. Excellent yield within short reaction time is obtained using microwave irradiation along with other advantages like mild reaction condition, non-hazardous and safer environmental conditions. The effects of temperature, reactant molar ratio, and microwave power variation on yield are observed. Mathematical model has been developed using matlab software to obtain the yield as a function of microwave power. Kinetic study of the reaction has also been attempted. Schiff’s bases structures are confirmed by IR, 1HNMR, Mass Spectra and elemental analysis.

Process Intensification of Continuous Flow Synthesis of Tryptophol

“…The microwave radiation is known to heat the reaction mixture rapidly and more uniformly because of rotational motion of molecules while trying to align themselves with the changing electric field of the microwave radiation. This leads to a different temperature–time profile for the reaction mixture as compared to conventional heating processes and therefore can lead to different distribution of products as the reactions have different activation energy values and can respond at differential rates to the temperature increase. − In the current work, the use of MW for heating allows the rapid temperature increase to be uniform throughout the reaction mixture, leading to no or little byproduct formation. The [3+3] sigma-tropic rearrangement, being more temperature-sensitive, is assisted by the thermal effect of the microwave radiation, at higher temperatures. − Thus, the intermediate undergoes faster transformation to final product, and the higher response to increased temperature within a short period because of small shelf life of intermediates limits the generation of byproducts.…”

A review on microwave-assisted synthesis and biomedical applications of Schiff bases

“…Chakraborty and co-workers synthesised various Schiff bases ( using different substituted aromatic amines and 3a-e) salicylaldehyde with methanol at 300 W from 30 secs to 2 mins. As a result, yellow-coloured amorphous products were obtained (Chakraborty et al, 2012) . A series of -Isatin (Scheme 3) β aldehyde-N,N'-thiocarbohydrazone Schiff base derivatives (4an) synthesised using thiocarbohydrazide and substituted aldehyde with glacial acetic acid as a catalyst at 160 W for 2 mins.…”

Microwave-Assisted Rapid and Green Synthesis of Schiff Bases Using Cashew Shell Extract as a Natural Acid Catalyst

“…The synthesis of organic molecules using microwaves has proven to be economical, clean, and environmentally friendly with a shorter reaction time. 4,5 Schiff bases are imine compounds with a −C�N bond linkage. 6 Schiff base derivatives play an important role in the field of inorganic medicinal chemistry.…”

“…In nonconventional processes, microwave-assisted synthesis has become an interesting method for researchers in the past few decades. The synthesis of organic molecules using microwaves has proven to be economical, clean, and environmentally friendly with a shorter reaction time. , …”

“…The synthesis of organic molecules using microwaves has proven to be economical, clean, and environmentally friendly with a shorter reaction time. 4 , 5 …”