Preparation of Na 2-n-Alkylindole Sulfonates and Their Physico-chemical Properties

Abstract

Three samples of sodium 2-n-alkylindole sulfonate [alkyl : heptyl (R-7 : abridged sign of this compound), undecyl (R-11), pentadecyl (R-15)] were prepared by the following process, _??_-CH3-NH2 RCOCl→-HCl_??_-CH3-NHCOR NaNH2→-H2O_??_-N-H-R H2SO4→-H2O NaO3S+_??_-N-H-Rand identified by elementary analysis, IR and NMR. The physico-chemical properties such as specific gravity, relative viscosity, surface tension, specific electrolytic conductivity. solubilization (dyestuff), sedimentation (CaCO3), emulsification (liquid paraffin) and wetting efficiency (feltcloth) were measured for the aqueous solution of these surfactants.The results obtained were as follows ;1) R-11 decreased the surface tension of water approximately to 4045 dynes per cm.2) R-15 was most excellent amoung many other surfactants in abilities of the solubilization of dyestuff, deflocculation of calcium carbonate and emulsification of liquid paraffin.