N-tert-Butylsulfonyl(Bus)-alpha-phenylaziridinyllithium was effectively generated by the reaction of N-Bus-2-phenylaziridine with n-BuLi in a microllow system at -28 degrees C, although much lower temperatures such as -78 degrees C are needed for batch reactors. Subsequent reactions with various electrophiles gave the corresponding alpha-substituted N-Bus-2-phenylaziridines. Deprotonation of N-Bus-aziridine with s-BuLi was also achieved by using a microflow system at -78 degrees C, and the reaction of the resulting N-Bus-aziridinyllithium with electrophiles gave the substituted N-Bus-aziridines.