ORIGINAL RESEARCH Synthesis of 3-(5-bromo-2,3-dimethoxy-phenyl)-[1, 2, 4] oxadiazole analogues and their evaluation as anti-Parkinson 0 s agents Shashi B. Tiwari Æ D. V. Kohli Received: 21 November 2007 / Accepted: 22 November 2007 / Published online: 28 March 2008 Ó Birkha ¨user Boston 2008 Abstract A series of 3-(5-bromo-2,3-dimethoxy-phenyl)-[1, 2, 4] oxadiazole derivatives was prepared and their evaluation for anti-Parkinson’s activity was measured in vivo using albino rats. The result of the biological activity studies indicated that some of the synthesized compounds have good agonistic activity on the dopamine receptors and a few of them were also found to be free from neurotoxicity. Thus these compounds might be useful ligands for studying the functional role of dopamine receptors in vivo. The high log P value of the com- pounds indicates that they should easily cross the blood-brain barrier (log P [ 2.6). Keywords Dopamine receptor antagonist Á Antiparkinson Á Oxadiazole Introduction Parkinson’s disease (PD) and Alzheimer disease (AD) are the most common neurodegenerative disorders. They affect at least 5% of the population above the age of 65 years (McDowell, 2001). The current drug therapy used for PD consists mainly of L-dopa and/or dopamine (DA) agonist, monoamine oxidase B inhibitors such as rasagiline, selegline, catechol-O-methyl transferase inhibitor (COMT), and OCH 3 H 3 CO Br N O N R S. B. Tiwari Á D. V. Kohli (&) Pharmaceutical Chemistry and Drug Design Research Laboratory, Department of Pharmaceutical Sciences, Dr. H. S. Gour University, Sagar, MP 470003, India e-mail: drdvkohali@rediffmail.com Med Chem Res (2008) 17:386–398 DOI 10.1007/s00044-007-9074-z MEDICINAL CHEMISTR Y RESEARCH