Protection of a primary amine group against attack by organic or aqueous solutions of strong bases or nucleophiles is achieved by incoporation into an N-substituted 2, 5-dimethylpyrrole system from which the amine group is regenerated by treatment with hydroxylamine hydrochloride.
[Bruekelman, Stephen P.; Leach, (Miss) Susan E.; Meakins, G. Denis; Tirel, Malcolm D. Journal of the Chemical Society, Perkin Transactions 1: Organic and Bio-Organic Chemistry (1972-1999), 1984 , p. 2801 - 2807]