Process for the manufacture of Degarelix and its intermediates

1. A process for preparing Degarelix having the formula Ac-AA 1 -AA 10 -NH 2 or a pharmaceutically acceptable salt or solvate thereof, wherein AA 1 is D-2Nal, AA 2 is D-4Cpa, AA 3 is D-3Pal, AA 4 is Ser, AA 5 is 4Aph(L-Hor), AA 6 is D-Aph(Cbm), AA 7 is Leu, AA 8 is Lys(iPr), AA 9 is Pro and AA 10 is D-Ala, comprising: treating a Degarelix precursor according to formula II (P 1 )AA 1 -AA 2 -AA 3 -AA 4 (P 4 )-AA 5 -AA 6 (P 6 )-AA 7 -AA 8 (P 8 )-AA 9 -AA 10 -NH 2 ), or a salt or solvate thereof, with a cleaving agent, wherein formula II is as follows:

wherein

P 1 is an amino protecting group;

P 4 is hydrogen or a hydroxyl protecting group;

P 6 is hydrogen or an amino protecting group;

P 8 is an amino protecting group; and

wherein the process is a liquid-phase process.

2. The process of claim 1 , wherein P 1 is acetyl; P 4 is a hydroxyl protecting group; P 6 is hydrogen or an amino protecting group; and P 8 is an amino protecting group.

3. The process of claim 2 , wherein P 1 is acetyl; P 4 is a t-butyl ether or ester (tBu); P 6 is hydrogen or tBu; and P 8 is t-butyloxycarbonyl (Boc).

4. A process for the manufacture of a decapeptide represented by formula (II)

(P 1 )AA 1 -AA 2 -AA 3 -AA 4 (P 4 )-AA 5 -AA 6 (P 6 )-AA 7 -AA 8 (P 8 )-AA 9 -AA 10 -NH 2   (II)

wherein AA 1 is D-2Nal, AA 2 is D-4 Cpa, AA 3 is D-3 Pal, AA 4 is Ser, AA 5 is 4Aph(L-Hor), AA 6 is D-Aph(Cbm), AA 7 is Leu, AA 8 is Lys(iPr), AA 9 is Pro, and AA 10 is D-Ala;

P 1 is an amino protecting group or acetyl;

P 4 is hydrogen or a hydroxyl protecting group;

P 6 is hydrogen or an amino protecting group; and

P 8 is an amino protecting group,

or a pharmaceutically acceptable salt or solvate thereof, comprising the step of coupling a first polypeptide represented by formula (III):

(P 1 )AA 1 -AA 2 -AA 3   (III)

or a salt thereof, with a second polypeptide represented by formula (IV):

AA 4 (P 4 )-AA 5 -AA 6 (P 6 )-AA 7 -AA 8 (P 8 )-AA 9 -AA 10 -NH 2   (IV)

or a salt thereof, in a liquid reagent medium in the presence of a peptide coupling reagent,

wherein the process is a liquid-phase process.

5. The process of claim 4 , wherein P 1 is acetyl; P 4 is a hydroxyl protecting group; P 6 is chosen from hydrogen and an amino protecting group; and P 8 is an amino protecting group.

6. A process for preparing a polypeptide represented by formula (IV):

(P 4 )AA 4 -AA 5 -AA 6 (P 6 )-AA 7 -AA 8 (P 8 )-AA 9 -AA 10 -NH 2   (IV)

wherein

P 4 is hydrogen or a hydroxyl protecting group;

P 6 is hydrogen or an amino protecting group; and

P 8 is an amino protecting group, comprising:

coupling a polypeptide represented by formulae (V), or a salt or solvate thereof, with a polypeptide represented by formula (VI), or a salt or solvate thereof,

(P N )AA 4 (P 4 )-AA 5 -AA 6 (P 6 )-AA 7   (V)

AA 8 (P 8 )-AA 9 -AA 10 -NH 2   (VI)

and then removing the deprotecting group P N , wherein AA 4 is Ser, AA 5 is 4Aph(L-Hor), AA 6 is D-Aph(Cbm), AA 7 is Leu, AA 8 is Lys(iPr), AA 9 is Pro and AA 10 is D-Ala, and P N is a protecting group that can be removed by hydrogenation,

wherein the process is a liquid-phase process.

7. The process according to claim 6 wherein P N is benzyloxycarbonyl which is removed by hydrogenating the compound (P N )AA 4 (P 4 )-AA 5 -AA 6 (P 6 )-AA 7 -AA 8 (P 8 )-AA 9 -AA 10 -NH 2 in the presence of a Pd/C catalyst.

8. A process for producing a compound of (P N )AA 4 (P 4 )-AA 5 -AA 6 (P 6 )-AA 7 , wherein AA 4 is Ser, AA 5 is 4Aph(L-Hor), AA 6 is D-Aph(Cbm), AA 7 is Leu, P 4 is chosen from hydrogen and a hydroxyl protecting group, P 6 is chosen from hydrogen and an amino protecting group, and P N is a protecting group that can be removed by hydrogenation, comprising the following steps:

(a) providing (P N2 )AA 5 -AA 6 (P 6 )-AA 7 (P C ), wherein (P N2 ) is an N-terminal amino protecting group or hydrogen, and (P C ) is a C-terminal carboxyl protecting group that can be cleaved by hydrogenation;

(b) removing the amino protecting group (P N2 ), if present;

(c) hydrogenating H-AA 5 -AA 6 (P 6 )-AA 7 (P C ) to obtain H-AA 5 -AA 6 (P 6 )-AA 7 ; and

(d) reacting H-AA 5 -AA 6 (P 6 )-AA 7 with an activated ester of (P N )AA 4 (P 4 ) to provide (P N )AA 4 (P 4 )-AA 5 -AA 6 (P 6 )-AA 7 , wherein (P 4 ) is a hydroxyl protecting group or hydrogen, and P N is a protecting group that can preferably be eliminated by hydrogenation,

wherein the process is a liquid-phase process.

9. The process according to claim 1 , wherein the pH is kept below 9.

10. Polypeptide compounds represented by the following formulae:

(P 1 )AA 1 -AA 2 -AA 3 ,

AA 4 (P 4 )-AA 5 -AA 6 (P 6 )-AA 7 -AA 8 (P 8 )-AA 9 -AA 10 -NH 2 ,

(P N )AA 4 (P 4 )-AA 5 -AA 6 (P 6 )-AA 7 -AA 8 (P 8 )-AA 9 -AA 10 -NH 2

(P N )AA 4 (P 4 )-AA 5 -AA 6 (P 6 )-AA 7

AA 8 (P 8 )-AA 9 -AA 10 -NH 2 ,

(P 1 )AA 1 -AA 2 -AA 3 -AA 4 (P 4 )-AA 5 -AA 6 (P 6 )-AA 7 -AA 8 (P 8 )-AA 9 -AA 10 -NH 2

or salts or solvates,

wherein AA 1 is D-2Nal, AA 2 is D-4 Cpa, AA 3 is D-3 Pal, AA 4 is Ser, AA 5 is 4Aph(L-Hor), AA 6 is D-Aph(Cbm), AA 7 is Leu, AA 8 is Lys(iPr), AA 9 is Pro, AA 10 is D-Ala;

P 1 is an amino protecting groups or acetyl;

P 4 is hydrogen or a hydroxyl protecting group;

P 6 is hydrogen or an amino protecting groups; and

P 8 is an amino protecting group, and P N is a protecting group.

11. The process according to claim 9 , wherein the pH is below 8.

12. The process according to claim 4 , wherein the pH is below 9.

13. The process according to claim 6 , wherein the pH is below 9.

14. The process according to claim 8 , wherein the pH is below 9.