Syntheses of N-substituted aziridines from aziridine-2-carboxylic acid methyl ester, aziridine-2-carboxamide and activated alkoxymethylenes were investigated. The latter included ethoxymethylene derivatives of isopropylidene malonate (Meldrum’s acid), (ethoxymethylene)malononitrile, ethyl (ethoxymethylene)cyanoacetate, and (1-ethoxyethylidene)malononitrile. It was demonstrated experimentally that the optimal reaction conditions include alcohols as a reaction medium and a temperature interval 0…40 oC. At higher temperatures one observes partial cleavage of aziridine ring. In the given conditions only the derivatives of Meldrum’s acid were active in the N-vinylation of aziridines. Acyclic analogs of activated alkoxymethylenes required higher reaction temperatures and thus individual products from these reactions were not isolated. On the other hand, cheap and efficient method for mild hydrolysis of aziridine-2-carbonitrile into aziridine-2-carboxamide was presented. The latter uses water as a solvent and acetone as an organocatalyst.