Process for the preparation of amezinium methylsulfate and evaluation of critical parameters for technology transfer

ORGN 73

Michael S. Allen, Sanjay R. Chemburkar, David N. Heinrichsmeyer, Brian J. Kotecki, Richard Lorenzini, Rajarathnam E. Reddy, rajarathnam.reddy@abbott.com, and Pulla R. Singam. Process Chemistry, MS&T, GPO, Abbott Laboratories, Abbott Park, IL 60064-6016
Amezinium methylsulfate (4-Amino-6-methoxy-1-phenyl)pyridazinium methylsulfate) is an anti-hypotensive and orthostatic dysregulation agent with novel adrenergic mechanism of action. Clinically, amezinium exhibits three individual actions such as (a) inhibition of intraneuronal monoamine oxidase, (b) release of noradrenaline, and (c) inhibition of noradrenaline re-uptake, and together they increases resistance and capacitance of vessels, and improves cardiac dynamics, which is reflected in rise of arterial pressure. Amezinium methylsulfate is synthesized from the commercially available 1-phenyl-4,5-dichloro-6-pyridazone in three stages based on the conversion of 5-chloride to amine followed by dehalogenation of 4-chloride and aromatization through methyl ether formation. In this poster, we describe the process for preparation of this novel anti-hypotensive agent, amezinium methylsulfate and evaluation of process critical parameters needed to support the transfer of technology from site to site.