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ABSTRACT:
An efficient synthesis of different novel 4,5-diphenyl pyrrole derivatives by the paal- knorr condensation has been accomplished using substituted aniline and 1,4 - diketone. The synthesized compounds were confirmed through spectral characterization using IR, 1H NMR. The pyrrole derivatives examined for their in vitro antimicrobial activity and in vivo anti- inflammatory. Result indicated that these compounds showed promising anti microbial and antiinflammatory activity in comparison to amoxicillin and ibuprofen (the standard antimicrobial and anti-inflammatory drugs). Tolmetin (Rumatol) and Ketorolac (Ketolac), nonsteroidal anti-inflammatory drugs (NSAIDs) containing pyrrole ring, are nonselective inhibitors of cyclooxygenase 1 and 2 enzymes that led to decrease prostaglandin synthesis.
KEY WORDS: Paal- knorr condensation, Pyrrole derivatives, anti-inflammatory.
INTRODUCTION
Pyrrole and the simple alkyl pyrroles are colourless liquids , with relatively eak odour s rather like that of aniline, which also like anilines, darkens by autooxidation .[1] The pyrrole scaffold is an useful structural pattern for exhibiting chemical functionality in biologically active molecules [1a]. it has established broad application in drug development for the treatment as antibacterial, anti-inflammatory, antiviral, antitumoral, and antioxidant agent [2]. The pyrrole ring system is one of the most important substructures for biologically active compounds such as indolizidine alkaloids, unsaturated g-lactams and bicyclic lactams. These structural units are found in a wide array of natural products, synthetic materials and bioactive molecules such as vitamin b12, heme and cytochromes therefore, preparation of pyrroles has attracted considerable attention of chemists in recent years. There are several methods for the synthesis of pyrrole in the literature from classical hantzsch procedure [5,6], 1,3-dipolar cycloaddition reaction , aza-wittig reaction , reductive coupling , titanium catalyzed hydroamination of diynes and other multistep operations . The most widely used method is the paal-knorr synthesis, which involves the cyclocondensation reaction of 1,4dicarbonyl compounds with primary amines to produce substituted pyrroles[9].
Chemistry-
Compound 1a-b was prepared by the reaction of benzoin with aniline (o-nitro, p-nitro) and malononitrile in ethanol solvent and utilized for...