| abstract |
It was found that the process for the nitration of halogenated aromatic compounds is improved by carrying out the nitration in the presence of a phosphorus compound in an amount sufficient to produce an ortho-directive effect. The addition of polyvalent metal elements such as vanadium, molybdenum, tungsten, and other elements that have the capability of existing in a variety of oxidation states, to a mixture of phosphoric and nitric acid improves the yield of the nitrohaloaromatics without affecting the isomer ratio. |