A Study of Oxygen Functional Groups in Illinois Coal Fractions

Ferric chloride/acetic anhydride reacted with butyl phenyl ether in acetonitrile at 80° to give a 75.6% yield of p-butoxyacetophenone. Reactions with benzyl aryl ethers gave 30% cleavage. The reaction of benzyl phenyl ether gave 10.3% p-benzyloxyacetophenone as well as cleavage product. Reaction of a pyridine soluble, toluene insoluble fraction (preasphaltene) of an Illinois No. 6 coal with ferric chloride/acetic anhydride in acetonitrile gave a product 94% insoluble in pyridine. The insolubility was ascribed to condensation reactions. Phenols were measured in coals, preasphaltenes and preasphaltene derivatives by acetylation with acetic anhydride in pyridine. Suggestions for improvement in the method were presented. Measurements over a period of time showed a decline in phenolic content in preasphaltenes that was attributed to air oxidation. No similar behavior was seen in the precursor coals. The insolubility of a preasphaltene of an Illinois No. 5 coal after drying was also evidence of air oxidation of that general fraction. Reaction of preasphaltenes with pyridine hydriodide gave no significant decrease in molecular weights. The apparent molecular weight reductions observed by other workers were hypothesized to be the artifactual result of iodide salt incorporations