synthesis of 2,3-dioxo-5-(substituted)arylpyrroles and their 2-oxo-5-aryl-3-hydrazone pyrrolidine derivatives合成2,3-dioxo-5 -(取代)arylpyrroles及其2-oxo-5-aryl-3-hydrazone吡咯烷衍生品.pdf

Molecules 2009, 14, 250-256; doi:10.3390/molecule OPEN ACCESS molecules ISSN 1420-3049 /journal/molecules Article Synthesis of 2,3-Dioxo-5-(substituted)arylpyrroles and Their 2-Oxo-5-aryl-3-hydrazone Pyrrolidine Derivatives M.F. Mohammat, Z. Shaameri and A.S. Hamzah * Organic Synthesis Laboratory, Institute of Science, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor, Malaysia * Author to whom correspondence should be addressed; E-mail: asazali@.my. Received: 13 October 2008; in revised form: 21 November 2008 / Accepted: 2 December 2008 / Published: 7 January 2009 Abstract: Some novel 2,3-dioxo-5-(substituted)arylpyrroles have been synthesized. Among these, pyrrolidine compound 1b was converted to 2,3-dioxo-5-aryl pyrrolidine 2b. Finally a set of hydrazone derivatives was obtained from the reaction of 2b with various hydrazine salts. The structures of all the new synthesized compounds were confirmed by elemental analyses, IR and 1H-NMR spectra. Keywords: Pyrrolidine; Hydrazine; Hydrazone; 2,3-Dioxo-5-(substituted)arylpyrroles. Introduction In connection with our ongoing studies towards the total synthesis of codonopsinine, we became interested in the three-component condensation reaction reported by Dehaen et al. [1]. This elegant one pot reaction furnished the important intermediate 2,3-dioxo-5-arypyrroles which are required in our work. Depending on the substitution groups on the aromatic aldehyde used, this reaction will provide different 2,3-dioxo-5-arylpyrroles in reasonable to moderate yields. Par