A continuous, solvent-free and non-enzymatic method for synthesizing a compound of formula (I): Ra-POLYPEP-Rc (I) wherein: POLYPEP is a poly-amino acid compound, Ra and Rc are as specified, the method including the steps of: a) feeding an extrusion reactor with (1) a compound of formula (II) Ra-PEPNt-Rg (II) wherein; PEPNt is a mono- or a poly-amino acid compound, Ra and Rg are as specified, and (2) a compound of formula (III) H-PEPCt-Rc (III) wherein: PEPCt is a mono- or a poly-amino acid compound, and Rc is as defined in the absence of any solvent, so that the compound of formula (II) and the compound of formula (III) react together for generating a compound of formula (I), and b) collecting the compound of formula (I) from the extrusion reactor.

An improved method of deprotection in solid phase peptide synthesis is disclosed. In particular the deprotecting composition is added in high concentration and small volume to the mixture of the coupling solution, the growing peptide chain, and any excess activated acid from the preceding coupling cycle, and without any draining step between the coupling step of the previous cycle and the addition of the deprotection composition for the successive cycle. Thereafter, the ambient pressure in the vessel is reduced with a vacuum pull to remove the deprotecting composition without any draining step and without otherwise adversely affecting the remaining materials in the vessel or causing problems in subsequent steps in the SPPS cycle.

The invention relates to a method for peptide synthesis, wherein said method comprises the steps of reacting a first amino acid or a first peptide with an α-amine protected second amino acid in a solvent selected from the group consisting of water, alcohol, and a mixture of water and alcohol, and removing the α-amine protecting group with a deprotecting solution. The invention further relates to protective agents, their use and an apparatus for carrying out a method for solid phase synthesis of peptides.

The present invention relates to the field of medicinal synthesis, and discloses a method for synthesizing degarelix. The method of the present invention as a whole divides the synthesis of degarelix into two parts from amino acids at positions 5 and 6, employs proper protective groups in part of the protected amino acids therein, and finally uses in association with a specific acidolysis agent to complete the whole synthesis process. In the present invention, a proper synthesizing scheme is selected, and adaptive protective group and acidolysis agent are selected, so that the overall synthesis process is optimized, the purity of degarelix is significantly improved with a higer total yield, and the production of the toxic hydantoin degradation product is avoided.

The invention provides a method for the cleavage of Fmoc group characterized by using a solution comprising 3-(diethylamino)propylamine. In particular, it provides a method for the preparation of peptides in solid phase wherein Fmoc protected amino acids are used and the Fmoc group is cleaved by a solution comprising 3-(diethylamino)propylamine.

A method for producing a cyclic peptide, including the following step (1) and step (2):

(1) a step of cyclizing a linear peptide; and

(2) a step of obtaining a cyclic peptide by adding a poor solvent to a mixture of the cyclic peptide and multimeric impurity, which mixture is obtained in the above-mentioned step, and filtering off the multimeric impurity as an insoluble material can efficiently remove multimeric impurity by-produced during a cyclization reaction, improve the purity of the obtained cyclic peptide, and reduce a burden on the purification step.

The invention relates to a method for preparing peptides comprising the step of forming a peptide bond wherein the carboxyl group of a first amino acid or first peptide is activated and an amino group of the first activated amino acid or first peptide is protected by a protecting group having a water-solubility enhancing group and the activated carboxyl group of the first amino acid or first peptide is reacted with an amino group of a second amino acid or second peptide wherein said carboxyl group of the first amino acid or first peptide is activated in the absence of the second amino acid or second peptide. The invention further relates to peptides comprising a protecting group having a water-solubility enhancing group being bound to the amino group and an activated or free carboxyl group.

The present invention relates to methods and compounds for the solid phase synthesis of peptides carrying a substituent at an amino group of an amino acid side chain.

The present disclosure relates generally to the field of polypeptide synthesis, and more particularly, to a linear solution phase synthesis of the Wnt hexapeptide Foxy-5 and protected derivatives and peptide fragments thereof.

The present invention relates to an improved process for the preparation of Cetrorelix acetate (1). More particularly, the present invention relates to the purification of Cetrorelix acetate (1) by simple method. ##STR00001##