Synthesis of N-urethane protected amino alkyl (S-methyl)-isothiouronium compounds and carbodiimide tethered peptidomimetics: an application for guanidino and substituted guanidino peptidomimetics synthesis

The synthesis of N, N'-disubstituted and N, N', N ''-trisubstituted guanidine linked peptidomimetic molecules suitably decorated in the peptide backbone has been delineated. N-alpha-Protected amino acid derived S-methyl isothiouronium derivatives are employed as the key intermediates for the synthesis of guanidinopeptide mimics. Synthesis of a new class of carbodiimide tethered dipeptidomimetics has also been outlined wherein a Staudinger-aza-Wittig type reaction between amino alkyl azide and isothiocyanato esters is employed. Thus obtained carbodiimides have been demonstrated as starting materials for the construction of guanidino peptide mimics as well as an array of trisubstituted guanidine mimetics bearing N-hydroxy, cyano and amino function as third substitutions at the guanidino unit in the backbone.