PREPARATION, CHARACTERIZATION AND UTILIZATION OF A NOVEL TRIFLUOROACETIC ACID SUPPORTED STARCH/GRAPHENE OXIDE GREEN NANOCOMPOSITE FOR EFFICIENT SYNTHESIS OF 2,4,5-TRISUBSTITUTED IMIDAZOLES

This study reports on the production, characterization, and application of a novel starch/graphene oxide nanocomposite for rapid synthesis of 2,4,5-trisubstituted imidazoles. To this end, graphene oxide was first functionalized by 1,8-diamino-3,5-dioxaoctane under appropriate conditions. Starch, functionalized graphene oxide, and 3-aminopyridine nanocomposite were then prepared from the reaction of starch with graphene oxide functionalized with 1,8-diamino-3,5-dioxaoctane in the presence of hexamethylene diisocyanate (HDMI) as a binding agent and 3-aminopyridine. Then, trifluoroacetic acid was added, giving rise to an acid-supported starch and graphene oxide nanocomposite. To examine the efficiency of the nanocomposite, 2,4,5-trisubstituted imidazoles were efficiently synthesized in the presence of the nanocomposite using benzil, aryl aldehyde, and ammonium acetate under solvent-free condition within a short reaction time. The moderate conditions, fast reaction rates, ease of purification, solvent-free condition, use of a green catalyst (nanocomposite), and environmental friendliness are among the advantages of the proposed synthesis method. The recoverability and durability of the catalyst were confirmed after five runs with no significant loss of activity. Thus, this research presents a novel nanocomposite based on starch and graphene oxide with superior properties.

Microwave assisted Acetylation of Amines using Imidazole Hydrochloride under solvent-free condition

A simple and novel microwave irradiation method has been developed for N-acetylation of both aliphatic and aromatic amines with N,N-dimethylacetamide via Nacetyl imidazole by using Imidazole hydrochloride under solvent-free condition. The method proved more eco-friendly and economic.

Solvent free synthesis of active 5-benzylidine-1, 3-thiazolidine-2,4-dione derivatives

Present communication describes the attempts made to improve the yields of thiazolidinedione group of derivatives keeping in view of their anti-cancer activity. 5-benzylidine-1,3-thiazolidine-2,4-dione derivatives were the active substrates belonging to α-glucosidase inhibitor classification. These were prepared by the reaction of 4-((Z)-(2,4-dioxothiazolidin-5-ylidene) methyl) benzaldehyde with aromatic/hetero aromatic ketones in the presence of potassium hydroxide and ethanol as solvent. Synthesis of 5-benzylidine-1, 3-thiazolidine-2,4-dione derivatives has been optimized under solvent free condition by screening with different bases in order to achieve the required target (of improving the yields). The solvent free condition has resulted in excellent improvement in yields and reduced the manufacturing cost significantly.

Green Synthesis and Biological Study of Pyrimidone derivatives employing Cetyltrimethyl ammonium bromide under solvent free condition

In this study, we are reporting a solvent free Biginelli reaction using aromatic aldehydes, ethyl acetoacetate and urea in presence of cetyl tri-methyl ammonium bromide as a catalyst. The reaction is green and environmentally benign. The yield of three component condensation reaction is excellent. The products were screened for anti-bacterial and anti-fungal activity. The method is simple and convenient. The catalyst is novel and easily available, non-expensive and nontoxic.

Recent development of green protocols towards Knoevenagel condensation: A Review

A large number of varied synthetic strategies for carbon-carbon bond formation have been proposed by researchers from time to time. Knoevenagel condensation products synthesized by green protocol have been highly appreciated, Knoevenagel products find enormous application in therapeutics and pharmacological. Green synthetic strategies like ionic liquid media, solvent free condition, use of aqueous media and utilization of nano particles towards synthesis of Knoevenagel products have been recently utilized by scientist all over the world. In this study we highlight the recent development of green methods for Knoevengal condensation product formation.

An efficient bifunctional ionic liquid [BIL] as solvent and catalyst system for O-alkylation of phenols under solvent-free condition- An environmental benign approach

: Bifunctional ionic liquid [BIL] was found to be a highly effective catalyst for the ether synthesis without any inorganic base or solvent. By this protocol, different aryl substitutions were reacted with different phenol in good to excellent yields. The BIL is reusable without any loss in catalytic activity for nine consecutive cycles. Background: The Williamson reaction is a convenient renovation in fine chemical synthesis since the ethers are important in both bulk and fine industrial chemicals preparation and academic applications. Objective: The aim of this study is to highlight the use of BIL to synthesize mixed ethers using substituted phenols and to study the reusability in the next cycle. Method: The mixture of the phenol (1mmol), alcohol (1.2 mmol) and BIL ionic liquid (0.3 mol%) was added in to round-bottomed flask (100 mL) with continuous stirring for 1 hour. Results: The products obtained were phenol and substituted phenols containing withdrawing substituents in respectable yields. However, the reactions involving substituted phenols containing electron-donating groups often afford the corresponding products in low yields. Conclusion: BIL is found to be an effective catalyst in the etherification of various unsymmetrical ethers under mild conditions. Bifunctional ionic liquid as a solvent and catalyst will show real rewards by providing a ‘green’ method with the safer procedure, less reaction time periods, mild conditions, separation easy, and ionic liquid recycle.