In the current research, a facile and green one pot synthesis of new gabapentin-lactams (G(2)-G(8)) has been achieved by reacting gabapentin (G(1)) with a variety of sulfonyl chlorides. The new lactamization protocol is furnished under the green solvent i.e., water and reaction was completed in a short period of time by just stirring at room temperature. Whereas in some cases, annulation could not happen and furnished un-cyclized sulfonamide products (G(9)-G(12)). The structures of the targeted compounds were established by elemental analysis, FT-IR, H-1-NMR and mass spectrometry. The crystals of some new lactams (G(2), G(3), G(4), and G(8)) were also evaluated by single crystal X-ray diffraction.