PURPOSE: To obtain the title compound which is used as an intermediate of medicines and agrochemicals, by allowing an organic base hydrofluoric acid salt and a nitrous acid donor to react with an aromatic compound bearing a hydroxyl group in the 4-position to the amino group, followed by diazotization and pyrolysis.

CONSTITUTION: 1) An organic base hydrofluoric acid salt solution and a nitrous acid donor are allowed to act on an aromatic compound bearing an amino group and hydroxyl in the 1,4-positions and hydrolyzed at a temperature over 50°C. Or 2) after action of hydrogen borofluoride and a nitrous acid donor, pyrolysis is carried out using an organic base hydrogen fluoride salt or 3) after use of a nitrous acid donor in the presence of hydrochloric acid, pyrolysis is effected using an organic base hydrofluoric acid salt to give an aromatic fluoride bearing a hydroxyl in the 4-position.