Abstract Semi-synthetic human insulin can be prepared by removing the Bchain C-terminal octapeptide from porcine insulin by trypsin hydrolysis followed by addition of the synthetic human insulin Bchain C-terminal octapeptide. The present disclosure relates to an improved process for preparing the precursor intermediate to the known synthetic human insulin octapeptide and to novel intermediates involved therein. This process uses a protected phenylalanine as the precursor for the protected tripeptide ZGly-Phe-Phe which is then condensed with the protected dipeptide HCL.Tyr(OBzl)-Thr-OCH3 to form the novel intermediate protected pentapeptide Z-Gly-Phe-Phe-Tyr-(OBzl)-Thr-OCH3. The pentapeptide is then converted to the hydrazide and coupled via azide coupling to the protected tripeptide HCl.Pro-Lys(Boc)-Thr-OCH3 to yield the novel protected octapeptide Z-Gly-Phe-Phe-Tyr(OBzl)-Thr-ProLys(Boc)-Thr-OCH3. The latter compound is converted to the known synthetic human insulin octapeptide derivative Gly-Phe-Phe-TyrThr-Pro-Lys(Boc)-Thr-OCH3 by hydrogenolysis.
AN IMPROVED PROCESS FOR THE PREPARATION OF THE TRIPEPTIDE Z-GLY-PHE-PHE WITHOUT RACEMIZATION OF THE REACTANTS OR INTERMEDIATES WHICH PROCESS COMPRISES: A. REACTING PHENYLALANINE WITH BOC-PHE-OSU IN A POLAR, NON-PROTIC SOLVENT IN THE PRESENCE OF AN ORGANIC BASE SO AS TO PRODUCT BOC-PHE-PHE, B. TREATING THE SAID BOC-PHE-PHE PRODUCED IN STEP A. ABOVE WITH TRIFLUOROACETIC ACID TO REMOVE THE BOC PROTECTING GROUP, AND C. REACTING THE RESULTING FREE DIPEPTIDE WITH A PROTECTED GLYCINE SELECTED FROM THE GROUP CONSISTING OF Z-GLYOSU AND Z-GLY-ONP IN A POLAR, NON-PROTIC SOLVENT IN THE PRESENCE OF A TRI-C1-7 LOWER ALKYLAMINE TO PRODUCE THE DESIRED Z-GLY-PHE-PHE.
Claim 3
Dependent Claim
26 words
The process of claim 3 wherein said polar, non-protic solvent in steps A and C is dimethylformamide and said organic base in step A. is 1,1,3,3-tetramethylguanidine.
Claim 4
Dependent Claim
22 words
The process of claim 3 wherein said protected glycine in step C is Z-GLy-OSu and said tri-C1 7 lower alkylamine is triethylamine.
Claim 5
Dependent Claim
132 words
An improved process for the preparation of the human insulin octapeptide derivative NH2-Gly-Phe-Phe-Tyr-Thr-Pro-Lys(Boc)-Thr-OCH3 which process comprises in combination: A. reacting the dipeptide Tyr(Bzl)-Thr-OCH3 with the tripeptide Z-Gly-Phe-Phe in the presence of a complex condensing agent comprising N-methyl morpholine, 1-hydroxybenzotriazole and dicyclohexylcarbodiimide to produce the pentapeptide Z-Gly-Phe-Phe-Tyr(Bzl)-Thr-OCH3; B. converting the pentapeptide produced in step A. into the corresponding hydrazide by reacting said pentapeptide with anhydrous hydrazine; C. reacting said pentapeptide hydrazide from step B. with a C1 7 lower alkyl nitrite in the presence of HCl dissolved in an organic solvent, followed by treatment with a tri-C1 7 lower alkylamine and then reaction with the tripeptide HCl.Pro-Lys(Boc)-Thr-OCH3 to produce the octapeptide NH2-Gly-Phe-Phe-Tyr(Bzl)-Thr-Pro-Lys(Boc)-Thr-OCH3; and, D. hydrogenating the octapeptide of step C. using a supported noble metal catalyst so as to produce the desired NH2-Gly-Phe-Phe-Tyr-Thr-Pro-Lys(Boc)-Thr-OCH3.
Claim 6
Dependent Claim
24 words
The process of claim 6 wherein said lower alkyl nitrite in step C. is iso-amyl nitrite and said tri-C1 7 lower alkylamine is triethylamine.
Claim 7
Dependent Claim
19 words
The process of claim 6 wherein said supported noble metal catalyst in step D is palladium on barium sulfate.