[Study on new anti-rust disinfectants. III. Effect of alkyl chain length of N-alkyl-N-(2-hydroxy-3-phenoxy)propyl-N,N-dimethylammonium butyl phosphate on the antibacterial activity].

New anti-rust quaternary ammonium salts such as N-alkyl-N-(2-hydroxy-3-phenoxy)propyl-N,N-dimethylammonium butyl phosphate (5) [alkyl homologues are octyl (5a), decyl (5b), dodecyl (5c), tetradecyl (5d), hexadecyl (5e), and octadecyl (5f)] were synthesized in order to find the relationship between the alkyl length and the antibacterial activities. N-Alkyl-N-(2-hydroxy-3-phenoxy)propyl-N,N-dimethylammonium chloride (6) [alkyl homologues are dodecyl (6c), tetradecyl (6d), hexadecyl (6e)] were used as standard compounds in the quantitative analysis. 5c and 6c showed antibacterial activities and these activities were nearly equal to that of benzalkonium chloride (BAC), but, the activities shown by 5e, 5f and 6e were insufficient. 5c-e, showed excellent anti-rust effects, but 6c-e showed insufficient effects, because the former had a butyl phosphate anion and the latter had a chloride anion as a counter ion. 5a, b were insoluble in water. 5c showed a cloud point at 61.5 degrees C and 5d showed a cloud point at 72.0 degrees C at a 10% concentration in water. This phenomenon is similar to those of non-ionic surfactants. 5e was freely soluble in water.