An effective and operationally simple method for the preparation of methyl 2-(di/tri/tetraazol-1-yl)-2H-azirine-2-carboxylates from accessible methyl 2-halo-2H-azirine-2-carboxylates and NH-azoles has been developed. The azoles having enhanced NH acidity, react with 2-halo-2H-azirines in the presence of Et₃N in a deprotonated form, while the azoles having highly nucleophilic sp² nitrogen react in neutral form. According to the DFT calculations, the substitution of the halogen by the azole proceeds via an S_N2′-S_N2′ cascade, with the initial conjugate substitution of the halogen being the rate-determining step. The formation of 2,3-dipyrazolylaziridines in the reaction of pyrazole provides experimental evidence for the cascade mechanism of the reaction.