Patent ID: 7897724

Claim:
A process for the preparation of a peptide N 6 -(aminoiminomethyl)-N 2 -(3-mercapto-1-oxopropyl-L-lysylglycyl-L-α-aspartyl-L-tryptophyl-L-prolyl-L-cysteinamide, cyclic(1→6)-disulfide of formula (1) on a solid support, said process comprising: a. assembling a peptide chain comprising of six amino acids and a thioalkyl carboxylic acid in a required sequence on a solid support to obtain a peptide bound resin of formula (2) as give below: (Trt)Mpr-Lys (Dde)-Gly-Asp(Otbu)-Trp-Pro-Cys(Trt)-solid support Formula (2); b. capping the free amino groups after each coupling of (a) with acetic anhydride; c. cleaving Dde group in the peptide of formula (2) from the solid support to obtain peptide solid support of formula (3) (Trt)Mpr-Lys-Gly-Asp(Otbu)-Trp-Pro-Cys(Trt)-solid support Formula (3); d. guanylating the peptide of formula (3) at ε-lysine-NH 2 in an organic solvent to obtain peptide-solid support of formula (4) as given below: (Trt)Mpr-Har-Gly-Asp(Otbu)-Trp-Pro-Cys(Trt)-solid support Formula (4); e. cleaving and deprotecting all groups in the peptide of formula (4) from the solid support the obtain peptide-amide formula (5) as given below: f. oxidizing the SH-peptide of formula (5) with an appropriate oxidizing agent to obtain the crude peptide-amide of formula (1); and g. purifying the crude peptide-amide of formula (1) by chromatographic technique.