Abstract: The present invention relates to compounds of the formula ##STR1## in which R.sup.1 and R.sup.2 are identical or different and are hydrogen or an alkyl radical having 1 to 18 carbon atoms and optionally containing oxygen, nitrogen or halogen, the radicals X, Y and Z are identical and are a fluorine, bromine or iodine atom or if two of the radicals X, Y or Z are identical or all of the radicals X, Y, Z are different from each other, X, Y and Z are a fluorine, chlorine, bromine or iodine atom. The invention further relates to a process for the preparation of the compounds, by reacting an aryldiazonium salt of the formula ##STR2## in which the radicals X, Y and Z are identical and are a fluorine, bromine or iodine atom or, if two of the radicals X, Y and Z are identical or all of the radicals X, Y, Z are different from each other, X, Y and Z are a fluorine, chlorine, bromine or iodine atom and A.sup.(-) is an anion of an acid having a pK.sub.a <7, with a compound of the formula ##STR3## in which R.sup.

Abstract: The present invention relates to a process for the preparation of isomerically pure 2-nitro-5-fluoro- or -5-chlorophenol, by reacting 2,4-difluoronitrobenzene or 2,4-dichloronitrobenzene with aqueous alkali metal or alkaline earth metal hydroxide solution or suspension in the absence of organic solvents or other solubility promoting substances at temperatures from about 20.degree. C. to about 190.degree. C., adjusting the pH of the reaction mixture to about 1 to about 6 by the addition of acid, steam distilling the resultant product and isolating it from the distillate after cooling.