Synthesis of peptides containing alpha, omega-diamino acids protected by phthalyl and t-butyloxycarbonyl groups

Claim 1

IN A PROCESS FOR THE MANUFACTURE OF PEPTDES BUILT UP FROM NATURAL A-AMINO ACIDS AND CONTAINING AT LEAST ONE NATURAL A,W-DIAMINO ACID BY CONDENSING IN A SERIES OF STANDARD PEPTIDE CONDENSATION REACTIONS MEMBERS SELECTED FROM THE GROUP CONSISTING OF NATURAL A-AMINO ACIDS, PEPTIDE BUILT UP FROM NATURAL A-AMINO ACIDS, AND DERIVATIVES THEREOF, THE STEPS WHICH COMPRISE (A) CONDENSING ONTO A CARBOXYLIC ACID DERIVATIVE OF A MEMBER SELECTED FROM THE GROUP CONSISTING OF A NATURAL A-AMINO ACID AND A PEPTIDE BUILT UP FROM NATURAL A-AMINO ACIDS IN WHICH ANY W-AMINO GROUP PRESENT IS PROTECTED BY THE PHTHALYL GROUP, A MEMBER SELECTED FROM THE GROUP CONSISTING OF A NATURAL A-AMINO ACID AND A PEPTIDE BUILT UP FROM NATURAL A-AMINO ACIDS IN WHICH THE A-AMINO GROUP IS PROTECTED BY THE TERTIARY BUTYLOXCARBONYL RADICAL, AND ANY W-AMINO GROUP PRESENT IS PROTECTED BY THE PHTHALYL GROUP, AND (B) AFTER EACH CONDENSATION SPLITTING OFF THE TERTIARY BUTYLOXYCARBONYL RADICAL AT A PH BELOW 4 AND, AT THE END OF ALL CONDENSATIONS, SPLITTING OFF ANY PHTHALYL GROUP BY MEANS OF HYDRAZINE IN A WEAKLY ACIDIC MEDIUM AT A PH FROM ABOUT 4 TO ABOUT 7.