The object is to provide a method suitably applicable to an industrial scale of efficientdeprotection reaction without the need of using any harmful solvent, and alsoprovide a process for producing a water-soluble azole prodrug with good efficiency.Thus, disclosed is a process for production of a salt represented by the formula(I): (I) wherein X represents a fluorine atom bound to position-4 or -5 in a phenylgroup. The process comprises step (a) wherein a compound represented by the formula(II) is subjected to a deprotection reaction in the presence of a carbocationscavenger: (II) wherein X represents a fluorine atom bound to position-4 or -5in a phenyl group.
