1,2,5-Substituted derivatives of 2-phenylpyrrolidine

The structures of the potential anti-human-immunodeficiency virus type 1 (HIV-1) non-nucleoside reverse transcriptase inhibitors (NNRTI) 1-tert-butoxycarbonyl-2-phenylpyrrolidine-2-carboxylic acid, C(16)H(21)NO(4), (I), and 2-ammoniomethyl-1-benzyl-5-oxo-2-phenylpyrrolidine chloride, C(18)H(21)N(2)O(+).Cl(-), (II), have been investigated by X-ray diffraction. The investigations confirm a butterfly-like conformation for both compounds. In (I), the pyrrolidine ring has a marked half-chair conformation, while it has a weakly pronounced envelope conformation in (II). Intermolecular hydrogen bonds, viz. O-H.O in (I), and N-H.O and N-H.Cl in (II), build infinite chains in both structures. Rotational disorder of the three methyl groups is observed in (I).