Syntheses and Evaluation of the Analgesic Activity of Some 4-Acetyl- 4-phenylpiperidine and 4-Hydroxy-4-phenylpiperidine Derivatives

4-phenylpiperidine and 4-Hydroxy-4-phenylpiperidine Derivatives Zafar Saeed Saifya, Khalid Mohammed Khanb, Syed Moazzam Haidera, Zeeshanb, Syed Tasadaque Ali Shahb, Muhammad Saeedc, Mohammed Saleh Shekhanid, and Wolfgang Voelterc a Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Karachi b International Center for Chemical Sciences, HEJ Research Institute of Chemistry, University of Karachi, Karachi-75270, Pakistan. Fax: 0092-21-4963373, 4963124. E-mail: dr_khalid60@hotmail.com c Abteilung fur Physikalische Biochemie, Physiologisch-chemisches Institut der Universitat Tubingen, Hoppe-Seyler-Strase 4, D-72076 Tubingen, Germany. Fax: (+49) 7071-293348. E-mail: wolfgang.voelter@uni-tuebingen.de d Ophidian Pharmaceuticals, Inc. 5445 E. Cheryl Parkway Madison, WI 53711 USA