C17H27N3O4S, Mr = 369.48, monoclinic, P2(1)/c, a = 13.333 (7), b = 7.946 (4), c = 17.550 (10) A, beta = 96.99 (4) degrees, V = 1845 (2) A3, Z = 4, Dm = 1.33, Dx = 1.330 Mg m-3, graphite-monochromated Cu K alpha radiation, lambda = 1.54178 A, mu = 1.744 mm-1, F(000) = 792, T = 293 K. Final R = 0.038 for 2405 unique observed reflections. The folded conformation of the molecule with the least-squares planes of the aromatic and the pyrrolidine rings almost perpendicular is essentially determined by intra- and intermolecular hydrogen bonds. In this way, two pseudorings are formed, one linking the amide H with the methoxy O, and a second one involving the 4-amino H and a sulfonyl O. An intermolecular hydrogen bond forces the planar amide group some 28 degrees out of the plane of the aromatic ring.