We have synthesized the novel 2-azetidinone derivatives by using Schiff bases of 1,2,4-triazoles via a single step protocol. We used DABCO as a good homogenous, ecofriendly, highly reactive, easy to handle, and nontoxic catalyst. In DABCO catalyzed synthesis of active 2-oxo-azetidine, a highly electrophilic ketene intermediate can react with weakly nucleophilic (N═CH) linkage, which is used as the precursor for the cycloaddition reaction to deliver the desired products in excellent yields with protic solvents. In addition, the DABCO as an economically viable and readily available catalyst is soluble in almost all solvents and their salts easily filtered off from the reaction medium. Moreover, this new synthetic protocol features high conversion in green solvents and a straightforward procedure.

The new approach involving the solid supported catalyst for the formation of C–N bond followed by cyclization has been reported. In this work we have reported a facile, efficient, and environment‐friendly protocol for the synthesis of some new 3‐amino‐imidazo[2,1‐b](1,3)benzothiazole derivatives by one‐pot condensation of 2‐aminobenzothiazole, indole‐3‐carbaldehyde, and aryl isocyanide in the presence of silica‐supported P2O5 as a heterogeneous solid acid catalyst. The reaction was performed using conventional method under green conditions. The present approach offers the advantages of simple methodology, inexpensive acid catalyst, short reaction time, easy work up with excellent yield, simple purification and use of green solvent. All the newly synthesized compounds were characterized in details using physical and chemical techniques such as melting point, 1H NMR, 13C NMR, and FTIR spectroscopy.

A series of 1,2,4-triazolyl-4-(5-indolylidene)-thiazolidinone derivatives were synthesized and screened for their antifungal and antioxidant activity. Among these synthesized compounds 3d, 3g showing good antifungal activity and compounds 3b, 3d, 3f and 3h have high % antioxidant activity with lower IC50 value of 11.21, 20.89, 17.51 and 14.05 respectively. We report the antioxidant potential of the said class of compound in which free radical is generated by methelenic and 2nd carbon of thiazolidinone ring. The antifungal activity reported against A. niger, C. albicans and A. flavus. The antioxidant activity of all the synthesized compounds was screened by H2O2, DPPH scavenging and by phosphomolybdenum method with respect to ascorbic acid.

A simple and efficient protocol for the synthesis of Schiff bases via condensation reaction of electron rich heterocyclic amines with electrophilic carbon of the carbonyl compound. Recently an impressive and important area in catalysis involved organic synthesis is the best implementation of Lewis acids as a acid catalyst for Schiff base synthesis. The higher acidic property and proper loading of catalyst leads to proper participation in reaction as a catalyst. The reactions of these Lewis acids are enhanced by porous solid support as heterogeneous catalyst. We report herein an efficient concise green synthesis of a new kind of β-lactam derivatives of 2-amino-6-nitro-benzothiazole via SiO2/P2O5 Lewis acid catalyzed Schiff bases. The reaction was carried out by the preparation of Schiff base through the condensation reaction of various aromatic aldehydes with substituted aromatic amines in the presence of P2O5/SiO2 under green conditions by simple conventional methods. Further this Schiff base used for the green synthesis of β-lactams by the reaction with chloro-acetyl chloride. The advantage of this reaction is good dispersion of active reagent sites, associated selectivity and easier work up with reusable catalyst. These qualities combined together prove these processes as truly eco-friendly green protocol with high product yields and short reaction time.