N-chloro-succinimide in methanol; acetic acid to a soln. of Hg-compd. in MeOH was added NaI in MeOH, then Na(125)I was added (10percent stoichiometric amount of NaI/Na(125)I), addn. of AcOH followed by addn. of NCS in MeOH, the mixture was stirred at 25°C for 20 min; the reaction was monitored by use of HPLC equipped with a UV detector, the yield was calculated by HPLC analysis of a solution of known concn., the established yield is the radiochemical yield;

N-chloro-succinimide in methanol; acetic acid to a soln. of Hg-compd. in MeOH was added one equivalent NaI in MeOH/AcOH and one equivalent NCS, the mixture was stirred for 15 min at 25°C; the reaction was monitored by use of HPLC equipped with a UV detector, the yield was calculated by HPLC analysis of a solution of known concn.;