Regiospecific Synthesis of 2,3-Disubstituted- -Histidines and Histamines

Regiospecific synthesis of 2,3-disubstituted- -histidines and 2,3-disubstituted histamines starting from -histidine methyl ester and histamine is reported. The key step involves homolytic free radical alkylation via silver catalyzed oxidative decarboxylation of alkylcarboxylic acids with ammonium persulfate.