Key Synthetic Intermediates for Biologically Active Heterocycles

The need and possibilities of synthesis of biologically active heterocycles and the preparation of intermediates capable of generating unusual side chains required for drug development work from simple precursors are discussed. In particular, using 1-aryl-2-nitro-1-alkenes and 2-chloro-3-formyl quinoline for the preparation of complex heterocycles and making accessible unusual side chains accessible via tetrahydrofuran-2-ones and 4-arylmethylene-isoxazolin-5-ones are described. 1. Introduction 2. Synthetic Precursors for Obtaining Heterocycles 2.1. 1-Aryl-2-nitro-1-alkenes as Precursors to Five-Membered Heterocycles and Their Annulated Derivatives 2.2. 2-Chloro-3-formylquinoline as a Precursor to Tri- and Tetracyclic Heterocycles with an Annulated Quinoline Ring 3. Synthetic Intermediates for Generating Compounds Required for Building Unusual Side Chains 3.1. Tetrahydrofuran-2-ones Used to Obtain Substituted Furans, Tetrahydroquinolines and Pentane Derivatives 3.2. 4-Arylmethyleneisoxazolin-5-ones as Synthetic Equivalents for Arylalkyl Ketones and Phenylpropylamines 4. General Importance