Aromatic nucleophilic fluorination

A process for the nucleophilic fluorination of a starting compound having at least one replaceable non-fluorine halogen or nitro substitutent on at least one aromatic ring having the structure ##STR2## where X is non-fluorine halo and/or nitro

• m is 1 to 6, R is hydrogen, hydrocarbyl, halogenated hydrocarbyl, amino, cyano and/or carbonylhalide,
• Y is CH or N, p is 0 to 5 and m+p is 1 to 6,
• to a compound having at least one more fluorine in the molecule than the starting compound which comprises the following steps:
• (1) intimately contacting the starting compound with an anhydrous molten composition containing at least 50 mole % of a compound or compounds having the formula MF.nHF wherein "M" is at least one of potassium, cesium, or rubidium, HF is hydrogen fluoride and "n" is a number from about 0.5 to about 2, at a temperature within the range of about 30.degree. C. up to a temperature below the decomposition temperature of said starting compound or said fluorinated compound, whichever is lower, at a pressure and for a time sufficient to yield at least one reaction product wherein at least one fluorine has replaced at least one non-fluorine halogen or nitro substitutent of said starting compound and a residual molten composition and (2) isolating and recovering the fluorinated reaction product from the residual molten composition.