Sulfonated Graphene Oxide Catalyzed Transformation of Pyrazole-Oxazolidine Derivatives and their Antimicrobial Activities

Abstract

In this work, biologically active novel (E)-5-((1-phenyl-3-(4-R-phenyl)-1H-pyrazol-4-yl)methylene)-3-(4-chlorophenyl)oxazolidine-2,4-dione derivatives are synthesized and characterized. Initially, 5-azanyl(4-chlorophenyl)carbamate (3) was obtained from 4-chloroaniline (1) via carbonation with CO₂ (2) in liquid ammonia, followed by O-carboxymethylation with sodium 2-chloroacetate to afford sodium 2-(((4-chlorophenyl)carbamoyl)oxy)acetate (4). Subsequently, compound 4 was cyclized to yield 3-(4-chlorophenyl)oxazolidine-2,4-dione (5) using sulfonated graphene oxide (SGO) as metal free nanocatalyst. Later, benzohydrazide (6) was condensed with various types of carboxylic acids (7) in presence of glacial acetic acid to obtain (E)-(4-R-phenyl)ethylidene hydrazone (8). It is further treated with POCl₃ at 80 ºC for 4 h to obtain substituted pyrazole derivatives (9a-h). Finally, substituted pyrazole derivatives (9a-h) treated with sulfonated graphene oxide (SGO) catalyzed product 3-(4-chlorophenyl)oxazolidine-2,4-dione (5) to obtain targeted heterocyclic molecules 10a-h. This protocol demonstrates significant advantages in efficiency, ecological sustainability and catalyst reusability. Furthermore, the synthesized 1,3-oxazolidine-2,4-dione derivatives were evaluated for their antibacterial properties. The findings highlight the catalytic potential of SGO in the synthesis of 1,3-oxazolidine-2,4-dione derivatives as well as in broader applications in green organic transformations.