One-Step Synthesis of Aromatic Terminal Alkynes from Their Corresponding Ketones under Microwave Irradiation Mohammad Ghaffarzadeh, Mohammad Bolourtchian, Zohreh Hassanzadeh Fard, Mohammad Reza Halvagar, and Farshid Mohsenzadeh Chemistry and Chemical Engineering Research Center of Iran, Tehran, Iran Abstract: One-step microwave-assisted synthesis of phenylacetylenes 2a – j from the corresponding ketones 1a – j in the presence of a new reagent, PCl 5 – pyridine, is described. The reaction is carried out under a simple operational and experimental procedure, avoiding the use of the complicated and harsh multistep reaction. Keywords: Microwave activation, One-step synthesis, PCl 5 – pyridine reagent, Phenylacetylene derivatives INTRODUCTION Acetylenic groups are important targets for organic chemists because of their applications and rich chemistry. [1] Conventional synthetic methods suggested in the literature for preparing these compounds [2] require multistep procedures with complicated preparation conditions, demanding vigilance during the whole reaction. [3] Although these methods are suitable for many synthetic routes, most of them have drawbacks such as applying sensitive chemicals (e.g., butyl lithium) and very low temperature (ca. 2788C) under an inert atmosphere. [4] Recently, novel procedures have been developed in which Received in Poland December 12, 2005 Address correspondence to Mohammad Ghaffarzadeh, Chemistry and Chemical Engineering Research Center of Iran, P.O. Box 14335-186, Tehran, Iran. Fax: þ98(21)88037185; E-mail: ghaffarzadeh_m@ccerci.ac.ir Synthetic Communications w , 36: 1973–1981, 2006 Copyright # Taylor & Francis Group, LLC ISSN 0039-7911 print/1532-2432 online DOI: 10.1080/00397910600634100 1973