EFFECT OF PHENOLS ON INTERFACIAL ACTIVITY OF CRUDE OIL (CALIFORNIA) CARBOXYLIC ACIDS AND IDENTIFICATION OF CARBAZOLES AND INDOLES

Progressive esterification of carboxylic acids, naturally occurring in a California crude oil, with diazomethane under conditions that leave phenols unmethylated is shown to result in an analogous progressive decrease of interfacial activity at alkaline pH. A quantitative correlation between carboxylic acid content and degree of interfacial activity is demonstrated. The effect of phenols on the interfaclal activity of carboxylic acids Is investigated by exhaustive methylation of both phenols and carboxylic acids followed by selective hydrolysis of the carbomethoxy groups. Accurate measurements of apparent interfacial activities of the hydrolysis products and functional group analysis by different quantitative infrared techniques show that phenols have a diminishing effect on the interfaclal activity of the carboxylic acids. The absence of significant quantities of porphyrins, primary and secondary amides, and thiols in the Interfacially active material is demonstrated. Indoles substituted on the pyrrole ring and/or carbazoles were identified as integral parts of the Interfacially active carboxylic acids. Identification was achieved by comparison of the free—NH— frequencies of active fractions with those of model compounds in the fundamental and in the near infrared regions. © 1969, American Chemical Society. All rights reserved.