Synthesis and Physicochemical and Antimicrobial Properties of N-2-(Alkylamino)ethyllglycine Dihydrochlorides

Abstract

Four N-[2-(alkylamino)]glycine dihydrochlorides [3](alkyl=octyl, decyl, dodecyl, and tetradecyl) have been prepared by the reaction of N-alkylethylenediamines with sodium chloroacetate in acieous methanol at 60°C for 6 h. Compounds [3] are nonhygroscopic, colorless crystals and behave in water as a triprotonic acid, having pKa' values (30°C) of 2.03, 8.74, and 10.36 for the octyl derivative. Compounds [3] are ampholytic surface-active agents. Their CMC values determined by surface tension and by conductivity measurements lay in the range from 0.24 mol/l for the octyl derivative to 0.0030 mol/l for the tetradecyl derivative. A linear relationship between the logarithm of CMC and the number of carbon atoms in the alkyl chain was found. Surface tension at CMC ranged from 32 to 40 dyn/cm. Compounds [3], especially the tetradecyl darivative, had a good antimicrobial activity against Staphylococcus aureus and Escherichia coli, but was far less effective against a fungus, Apergillus oryzae.