Si trova su / Altri legami
© An efficient procedure to access tritium–labeled maleimide derivatives in a high specific activity has been developed. N–Substituted maleimides containing the hydroxy functionality are O–methylated in a three–step synthesis route, including (1) Diels–Alder protection of the maleimide core, (2) O–methylation by the use of commercially available [3H]methyl nosylate, and (3) deprotection by retro–Diels–Alder reaction. With our procedure, N–hydroxyalkyl maleimide derivatives can be labeled in overall radiochemical yields of 13–15% and in >98% radiochemical purity. The major advantage of N–alkoxy maleimides in comparison to N–alkylated maleimides such as N–ethylmaleimide is their lower volatility, which enables safer handling with respect to radiation–safety protection. Tritium–labeled maleimide building blocks allow subsequent Michael–type conjugation reactions of thiol–containing biomolecules for mechanistic in vitro or in vivo studies.
