Synthesis of 8‐cyano‐1,4‐dihydro‐4‐oxopyrrolo[1,2‐a]pyrimidine‐3‐carboxylic acids as potential antimicrobial agents

Abstract

The preparation of a variety of 8‐cyano‐1,4‐dihydro‐7‐phenyl‐4‐oxopyrrolo[1,2‐a]pyrimidine‐3‐carboxylicacids and 8‐cyano‐1,4‐dihydro‐7‐p‐fluorophenyl‐4‐oxopyrrolo[1,2‐a]pyrimidine‐3‐carboxylic acids is described.

EMCA and DEEM as Michael Reagents Used in Organic Synthesis

“…The basicity of nitrogen in the pyrrole ring is so low that using strong acid catalysts (PPA-POCl 3 ) [133][134] or highly-boiling aprotonic solvents (isobutylbenzene) [134] is essential. The condensation of DEEM with 2-iminopyrrolidine derivatives is much easier.…”

“…25) were obtained from 2-aminopyrrole and DEEM in isobutylbenzene, the mixture of PPA and POCl 3 [133][134] or by heating without a solvent in high temperature [137][138][139][140].…”

Isoxazole Strategy for the Synthesis of α-Aminopyrrole Derivatives

“…We mention here only the recently published work on this topic: derivatives of 2-amino-1-benzyl-4,5-diphenyl-1 H -pyrrole-3-carbonitrile are a broad spectrum inhibitor of metallo-β-lactamases; 2-amino-5-benzoyl-4-(2,4-dichlorophenyl)-3-(3-chlorobenzoyl)-1 H -pyrrole is a potent and selective human 15-lipoxygenase-1 inhibitor; ethyl-2-amino-pyrrole-3-carboxylates are potent anticancer agents that affect tubulin polymerization, induce G2/M cell-cycle arrest, and effectively inhibit soft tissue; 5-acetyl-2-((2-fluoro-4-iodophenyl)­amino)-1 H -pyrrole-3-carboxamides are inhibitors of MEK kinase . Pyrroles with an unsubstituted pyrrole nitrogen and α-amino group have a special importance, being precursors for pyrrole-fused nitrogen polyheterocycles . Unexpectedly, we found that approaches to such derivatives of pyrrole are quite limited.…”

Formal synthesis of salinosporamide A via NHC-catalyzed intramolecular lactonization

“…Toward this end, aldehyde 1 was synthesized by the coupling of 2 9 and acid 3 (Scheme 1). However, when 1 was allowed to react with commercially available NHC precatalysts IMesCl or RMesCl10 in THF at 40 °C in the presence of DBU, the desired product was not observed but rather the N -substituted succinimide 4 was obtained exclusively via NHC-catalyzed redox generation of the activated carboxylate (Scheme 1).…”