N-Unsubstituted 3,4-difluoropyrrole is synthesized via a thermal [2+3]
cycloaddition reaction of a N-tert-butyl 2-alkoxycarbonyl aziridine a
nd chlorotrifluoroethylene. Dealkylation of an intermediate N-tert-but
ylpyrrole is obtained with trifluoromethanesulfonic acid.