A manufacturing process for the preparation of radiolabeled compounds of formula (I)includes reacting compounds of formula (II) with a source of readionuclide of a halogen in the presence of an oxidant under acidic condition,wherein: *I is 123I, 124I, 125I or 131IR is lower alkyl, optionally substituted with one or more fluorine atomsQ is C(O), O, NR′, S, S(O)2, C(O)2, (CH2)pY is C(O), O, NR′, S, S(O)2, C(O)2, (CH2)pR′ is H, C(O), S(O)2, C(O)2Z is H, C1-C4 alkyl, benzyl, substituted benzyl or trialkylsilylm is 0, 1, 2, 3, 4 or 5n is 0, 1, 2, 3, 4, 5 or 6 andp is 0, 1, 2, 3, 4, 5 or 6.
