Victor V. Shtamburg

A new synthesis of N-alkoxyaminopyridinium salts

It was found, that methyl N-alkoxy-N-chlorocarbamates interaction with 4-dimethylaminopyridine was overall manner of synthesis of 1-N-alkoxyaminopyridinium chlorides. New1-N-n-octyloxyamino-4-dimethylaminopyridinium and 1-Nbenzyloxyamino-4-dimethylaminopyridinium chlorides have been synthesized by the methyl N-chloro-N-n-octyloxycarbamate and methyl N-benzyloxy-N-chlorocarbamate interaction with 4-dimethylaminopyridine in acetonitrile solution, respectively. The novel synthesis of 1-N-alkoxyaminopyridinium chlorides by reaction of N-алкоксимочевин alkoxy-N-(1pyridinium)ureas chlorides ammonolysis has been proposed. 1-N-Methoxyamino-4-dimethylaminopyridinium chloride and 1N-n-butyloxyamino-4-dimethylaminopyridinium chloride have been synthesized by reaction of N-1-4-dimethylaminopyridiniumN-methoxyurea chloride and N-n-butyloxy-N-(1-4-dimethylaminopyridinium)urea chloride, respectively, with excess of ammonia in ethanol solution at room temperature during few minutes. Evidently, the carbamoyl proton elimination by ammonia causes further formation 1-N-alkoxy-4-dimethylaminopyridinium chlorides and HNCO. It is new example of decarbamoylation of N-alkoxy-N-(1-pyridinium)ureas salts. 1-N-Metoxyamino-4-dimethylaminopyridinium fluoride has been synthesized by N-1-(4-dimethylamino)pyridinium-N-methoxyurea chloride reaction with potassium fluoride in acetonitrile. Probably, in this reaction N-1-(4-dimethylamino)pyridinium-N-methoxyurea caution decarbamoylation occurs after the chloride anion exchange on fluoride anion. 1-N-Alkoxyaminopyridinium salts structures have been confirmed by data of NMR 1H spectra, NMR 13C spectra and mass-spectra.

Synthesis and Structure of New N-Alkoxy-N-(1-pyridinium)urea Chlorides

New N-[1-(4-amino)pyridinium]-N-methoxyurea chloride, N-[1-(2-amino)pyridinium]-N-methoxyurea chloride and their analogs were synthesized by N-alkoxy-N-chloroureas reaction with the proper pyridines in acetonitrile or ether solution by improved procedure. XRD study of N-[1-(4-amino)pyridinium]-N-methoxyurea and N-[1-(2-amino)pyridinium]-N-methoxyurea revealed the elongation of N-N + bonds and some shortening of MeO-N bonds, qunonoid deformation of pyridine rings compare to it unsubstituted analog. The substantial pyramidality of central nitrogen atom in O-N-N + moiety and N-C carbamoyl bonds difference were established too. The structure summary of N-alkoxy-N-(1-pyridinium)ureas salts and other derivatives of 1-(N-alkoxyamino)pyridinium salts has been done.