Soap-based detergent formulations: XXIII. Synthesis of p-sulfobenzyl ammonium inner salts and structural correlation with analogous amphoterics

Two series of p-sulfobenzyl ammonium inner salts, RN⁺(CH₃)₂CH₂C₆H₄SO₃^? and RCONH(CH₂)₃N⁺?(CH₃)₂CH₂C₆H₄SO₃^?, where R is a straight chain alkyl group, were prepared by sulfonation of the corresponding quaternary ammonium chlorides. Although both series have excellent lime soap dispersion properties, the former series gave optimum detergency at considerably shorter alkyl chain length than the latter serires. The detergency, lime soap dispersion ability, and solubility of these compounds were compared with those of structurally analogous aliphatic sulfobetaines. Structural variations, such as length and nature of the bridge between the cationic and anionic groups, length of the lipophilic chain, and insertion of an amidopropyl group into the lipophilic portion of the molecule, significantly altered the detergency and solubility but not the lime soap dispersing ability of the amphoterics.