Abstract
The behaviour of humic acid obtained from coal is affected by its oxygencontaining functional groups, especially carboxylicgroup.The carboxylic group of the humic acid (obtained from Onoura bituminous coal by oxidation with 1N-HNO3) was converted into other various functional groups, and discussed about these conversion processes and properties of the obtained derivatives.
In the first series, the expected reactions occured smoothly, and the content of etherlinkage was estimated. In the second series, the acid chlorid (Hm) (OCH3) (COCl) was obtained in good yield, however, the subsequent conversions were incomplete. It is supposed that these low yields are caused by complex chemical structure of the humic acid.
Then, the rational formula of the humic acid and the solubility of some derivatives were discussed.
