Studies On The Synthesis Of AMPB And Methoxy Derivative And Its Application

1-Amino-2-methyl-pyridinium Bromide(AMPB)compounds,as an important drug intermediates and dye intermediates,are mainly synthesized antiasthmatic drugs ibudilast,etc..It can also be used to synthesize some high value new pharmaceutical intermediates.In the literature,the AMPB was prepared from 2-methyl-pyridine as a raw material,through tosylate N-amination,and bromide salt formation.The relative yield is relatively low and the "three wastes" treatment is relatively difficult.The 1-Amino-2-methylpyridinium Bromide(AMPB)compounds were prepared from 2-methyl-pyridine and Hydroxylamine-O-sulfonic acid(HOSA)via azoamidation,neutralization,and salt formation.The experimental study confirmed the feasibility of the road.Meanwhile,This paper was focused on product quality,yield a number of factors to determine the relatively optimum conditions Then on this basis,further exploration has been made in the industrial pre-production.10-Methoxy-4H-benzo[4,5]cyclohepta[1,2-6]thiophen-4-one is the key inter-mediate of antiallergic ketotifen fumarate.10-methoxy-4H-benzo[4,5]cyclohepta[1,2-b]thiophen-4-one were prepared from 2-[2-(2-thienyl)ethenyl]benzoic acid via hydrogenation,cyclization,bromination and methoxylation.At the same time,in the complete underbrush and reference of domestic and foreign similar products based on technology,we designed a industrialization production line,and it had conducted a successful trial production.Compared to other synthesis methods,the process has the process simple,safe,low cost,high yield(which can be over 75%),easy to industrialization and so on.