A process for the production of a compound of formula (III) which comprises a step of reacting a compound of formula (I) with an excess amount of a compound of formula (II) in absence of aromatic solvent, wherein n is 0, 1, 2, 3 or 4; X is NH, O or S; each R1 group may be the same or different, and is independently selected from the group consisting of hydrogen, hydroxyl, alkoxy, alkyl, carbonyl, carboxyl, carboxylic acid ester, amido, cyano, halogenated aliphatic, nitro, and amino; and R2 group is selected from the group consisting of hydroxyl, Cl, F, Br, amino, and alkoxy.