Process for the preparation of aryl diazonium fluorides and aryl fluorides

摘要

An aryl fluoride is prepared by the production of an aryl diazonium fluoride by the reaction, in liquid anhydrous hydrogen fluoride, at a temperature below the decomposition point of the diazonium fluoride produced, of an aromatic primary amine with either nitrosyl fluoride, or a nitrosyl fluoride complex of formula NOF.xHF where x is 3 or 6, or a mixture of the said fluoride and said complexes, and the subsequent decomposition by heat of the diazonium fluoride produced. The preferred amine is a monoamine in which the aromatic nucleus is that of a mononuclear aromatic hydrocarbon or a derivative thereof containing one to three substituents selected from alkoxy groups containing 1 to 6 carbon atoms, bromo, chloro, carboxyl, m-hydroxy, o-hydroxy, nitro, and sulphonic acid radicals. The diazotization is preferably effected in the temperature range of -30 DEG C. to +10 DEG C. and the decomposition in the range 25 to 70 DEG C. In examples, aniline, 4-cumidine and m-aminophenol are converted into fluorobenzene, 4-fluorocumene and m-fluorophenol, respectively. Other amines are also specified. Specification 941,537 is referred to.