Two properly substituted sulphonamidoimidazolines suitable for chelation have been synthesized from aspartic acid. The structures of these compounds have been established on the basis of their elemental analysis, synthetic route, IR, NMR and pK* values. The inhibiting action of the imidazoline derivatives namely alpha-benzenesulphonamido-beta-(2-imidazolynyl) ethanoic acid (R(m)H) and 1-benzenesulphonamido-1, 2-bis (2-imidazolynyl) ethane (R(b)H) on the corrosion of brass in 0.6 M aqueous NaCl solution have been studied. RbH is found to be a better inhibitor than RH. Difference in inhibition efficiency between R(m)H and R(b)H is correlated with their chemical structures. It has been observed that in presence of cysteine, inhibition efficiency of R(m)H is increased.