PRODUCTION OF P-FLUOROPHENOL

PURPOSE:To safely obtain the subject compound in high yield and high purity on an industrial scale by diazotizing p-aminophenol with an alkyl nitrite in the presence of an aqueous solution of hydrofluoric acid having a specific concentration and heat-decomposing the resultant diazonium salt. CONSTITUTION:p-Aminophenol of formula I is reacted with a diazotizing agent in the presence of hydrogen fluoride and the obtained diazonium salt of formula II is subjected to thermal decomposition usually at about 20-200 deg.C, preferably at about 30-150 deg.C to obtain p-fluorophenol of formula III useful as all intermediate for pharmaceuticals, agricultural chemicals or dyes. In the above process, the diazotizing reaction is carried out with an alkyl nitrite of formula IV (R is CnH2n+1; n is integer of >=1) in the presence of an aqueous solution of hydrofluoric acid having a concentration of 40-90wt.% at -100 to +150 deg.C, preferably -80 to +100 deg.C. The objective compound can be produced in high purity and yield at a low cost.