Green Synthesis of Chalcone Derivatives Using Chalcones as Precursor

Abstract

Recently, the use of green methodologies like sonication, use of ionic liquids, etc. attracted the attention of researchers in the field of organic synthesis as they have advantages such as mild reaction conditions, environmentally benign procedures, etc. Herein, this chapter highlights some recyclable ionic liquids (ILs) catalyzed ring closure reactions of chalcones to obtain several heterocyclic rings viz.; pyrazoles, pyrans, pyrimidines under ultrasonification. These reactions have very important features i.e., short routine, high yields, being environmentally friendly, high functional group tolerance, formation of a single product, high atom economy, high yielding, no need for column purification, etc. The various synthesized compounds were prepared in optimized reaction conditions in good to efficient yields. Analytical and spectral (FTIR, 1H, and 13C NMR) techniques were employed for the structural elucidation of the synthesized compounds. The ionic liquids used in the synthesis are recycled and reused several times.

Synthesis ,Characterization and Antioxidant Activity of Schiff base derivatives from [6,6'-(1,4-phenylene)bis(4-(4-aminophenyl) pyrimidin)]

“…SH and C-S stretching for compound (2) around 2640 cm -1 and 729.9cm -1 , respectively. The compound (3) appearance new stretching band for (OH) in 3205cm -1 .The FTIR spectral data of these compounds are shown in Table (2). TetraMethylSilane (TMS) was used as an internal standard in the 1 H NMR analysis of heterocyclic compounds (2and 3) in DMSO, [6,6'-(1,4-phenylene)bis(4-(4aminophenyl) pyrimidin-2-thiol)](compound2) which revealed the following signals: A doublet signal in the region of 7.89 ppm could be attributed to two protons of the pyrimidine ring, a sharp singlet signal at 6.07 ppm due to the four proton of the two amine groups, and a singlat signal in the region of 6.62 ppm for two protons of the (SH) groups substituted in heterocyclic, where [6,6'-(1,4phenylene)bis(4-(4-aminophenyl) pyrimidin-2-ol)](compound3) appeared doublet signal in 7.56 ppm to two protons of the pyrimidine ring, a singlet signal at 6.06 ppm to the four proton of the two amine groups, and a singlet signal in the region of 8.78 ppm for two protons of the (OH) groups substituted in heterocyclic Table (3) displays the 1 HNMR spectral information for these substances.…”

“…Scheme (One technique to gauge a substance's antioxidant strength is to assess its ability to scavenge DPPH, which can be done by observing a decrease in the maximum DPPH absorption at 570 nm (14). The compound (2) and Schiff bases derivative it's appeared antioxidant activity compare with the compound (3) and its derivative. The antioxidant activity of the created heterocyclic compounds was shown in table (7)…”

The green chemistry of chalcones: Valuable sources of privileged core structures for drug discovery

“…Recently, the research group of Dhadda, has applied together with the use of ionic liquids with the technique of sonication and managed to create a scheme for different synthetic heterocyclic compounds, including 2-amino-3,4-pyrimidine, pyrazole, oxazole, and pyridine derivatives. The basic ionic liquid [DBUH]OAc has proven to be the best IL since it leads to obtaining good yield of the desired result and it can also be reused for up to five catalytic cycles ( Dhadda et al, 2022 ).…”

“…Frontiers in Chemistry frontiersin.org (Sharma et al, 2022). The click reaction can be carried out under ultrasonication to enhance the reaction rate as reported by Kaur, the reaction was performed with variably substituted aromatic azides and terminal alkynes (Figure 9E) (Kaur et al, 2022).…”

Green synthesis, structure–activity relationships, in silico molecular docking, and antifungal activities of novel prenylated chalcones

“…Scientists are gradually focusing more on ecofriendly methods of chemical syntheses, with particular attention to designing efficient catalysts and advancing green chemistry principles. In recent times, a number of chalcone derivatives have been synthesized utilizing ionic liquids (ILs) as both the solvents and catalysts for the ring-closure reactions of chalcones ( Dhadda et al, 2022 ). Moreover, nanocatalysts have been utilized as green alternatives to conventional catalysts in the synthesis of numerous chalcone derivatives ( Jain et al, 2021 ).…”