| abstract |
ABSTARCT A crude 3,3'-dinitrodiphenyl compound selected from 3,3'-dinitrodiphenylsulfone or 3,3'-dinitro-benzophenone is purified by reacting the crude 3,3'-dinitrodiphenyl compound with a lower alcohol in the presence of a base so as to convert practically the isomer or isomers, which contain one or more nitro groups at the ortho- or/and para-positions, only into the corresponding alkoxy compound or compounds thereof and then separating the alkoxy compound or compounds. |