Synthesis of Indolizine Derivatives and Their Reactions. II

Abstract

1-Azaindolizine derivatives (Va, b, c) were easily obtained by the reaction of dimethyl N-(2-methylpyridin-5-yl) dithiocarbimidate (III) and α-halogenocarbonyl derivatives (ethyl bromoacetate, ω-bromoacetophenone, and ethyl bromocrotonate). 1-Azaindolizine derivatives (II, Va) were oxidized with perphthalic acid to afford 2-methylsulfonylimidazo-[1, 2-a] pyridine derivatives (VIa, b). Va was brominated with N-bromosuccinimide to ethyl 5-bromomethyl-2-methylthioimidazo [1, 2-a] pyridine-3-carboxylate (XII), which reacted with ammonia and methylamine to afford dihydrodiazacycl [3.2.3] azine derivatives (XIII, XIV).