PURPOSE: To obtain the subject compound simply and safely in high yield without producing any by-products by reacting a nitrobenzoic acid with an alkanol in the presence of a catalyst being a polyfluoroalkanesulfonic acid under specified conditions in a solvent.
CONSTITUTION: A nitrobenzoic acid (e.g. 2-nitrobenzoic acid) as a starting compound is reacted with about 300 to about 600 mol.%, desirably about 400 to 500 mol.% excess 1-3C alkanol in the presence of about 0.1 to about 20 mol.%, especially about 2 to 4 mol.%, based on the nitrobenzoic acid used as the starting compound, compound of the formula (wherein Y is H or F with the proviso that, when Y is H, the H is in position β to the sulfo) or a hydrate thereof at about 60-120°C, especially 62-95°C in an inert solvent sch as benzene or propyl isopropyl ether to obtain the objective compound.
RAINERU HESU
ANDOREASU FUSU
