Chemical and Kinetic Study on Stabilities of 3-Morpholinosydnonimine and Its N-Ethoxycarbonyl Derivative

Abstract

Stabilities of 3-morpholinosydnonimine (II), hydrochloride (I) and N-ethoxycarbonyl-3-morpholinosydnonimine (VIII) were examined by photometry, potentiometry, thin-layer chromatography and spectroscopy. In alkaline solution VIII goes to ethanol, carbon dioxide and II, which successively decomposes to N-morpholino-N-nitrosoaminoacetic acid (V) and N-cyanomethylenaminomorpholine (VI) via N-morpholino-N-nitrosoaminoacetonitrile (III). In the processes of I=II=III, the initial equilibrium is very rapid and the consecutive cleavage is a spontaneous first order reaction at pH 3-7 or a base catalyzed reaction at pH 8-10. The initial process of is a base catalyzed. first order hydrolysis of N-ethoxycarbonyl group. Hydrolyses of I and VII in hydrochloric acid form morpholine, nitrogen, chloroacetic acid and ammonium chloride. Photolyses of I and VII in acid solution at γ<320mμt give glycolic acid beside the products mentioned above. Formation of I from III and hydrolysis of VI to N-aminomorpholine are acid catalyzed pseudo-first-order reactions. Decomposition of III to VI seems to be a radical reaction.