Peptide boronic acids useful in making salts thereof

• US 20050176651A1
• Filed: 09/08/2004
• Published: 08/11/2005
• Est. Priority Date: 09/09/2002
• Status: Abandoned Application

• Current Assignee: Paion Deutschland GmbH (PAION AG)
• Original Assignee: Trigen Limited
• Inventors: Olbrich, Alfred, Deadman, John Joseph, Krimmer, Dieter, Dolman, Mark, Madge, David Jonathan, Walter, Armin, Weiland-Waibel, Andrea M.T.
• Application Number:
  US10/937,854
• Publication Number:
  US 20050176651A1
• Time in Patent Office: Days
• US Class Current: 514/14.700
• CPC Class Codes: C07F 5/025 Boronic and borinic acid compounds
• CPC Class Codes: C07K 5/06078 and aromatic or cycloaliphatic

Abstract

Tripeptide boronic acids of (R,S,R) configuration, for example Cbz-(R)-Phe-(S)-Pro-(R)-Mpg-B(OH)₂, and their use to make base addition salts of such acids. The salts are formulated into anti-thrombotic pharmaceutical formulations.

Claims

1. An isolated compound selected from boronic acids of formula (IIIa):

2. A compound of claim 1 wherein aa¹ is selected from Dpa, Phe, Dcha and Cha.

3. A compound of claim 1 wherein aa¹ is Phe or Dpa.

4. A compound of claim 2 wherein aa² is a residue of an imino acid of formula (IV)

5. A compound of claim 4 wherein R¹ is a group of the formula —

(CH₂)_s-Z, where s is 2, 3 or 4 and Z is —

OH, —

OMe, —

OEt or halogen.

6. A compound of claim 5 wherein the boronic acid is of formula (VIII):

X-(R)-Phe-(S)-Pro-(R)-Mpg-B(OH)₂ 

 

(VIII).

7. A compound of claim 5 where X is R⁶—

(CH₂)_p—

C(O)—

, R⁶—

(CH₂)_p—

S(O)₂—

, R⁶—

(CH₂)_p—

NH—

C(O)—

or R⁶—

(CH₂)_p—

O—

C(O)—

wherein p is 0, 1, 2, 3, 4, 5 or 6 and R⁶ is H or a 5 to 13-membered cyclic group optionally substituted by 1, 2 or 3 substituents selected from halogen, amino, nitro, hydroxy, a C₅-C₆ cyclic group, a C₁-C₄ alkyl group, a C₁-C₄ alkyl group containing an in-chain O, a C₁-C₄ alkyl group containing an in-chain O and linked to the cyclic group through an in-chain O and a C₁-C₄ alkyl group linked to the cyclic group through an in-chain O, the aforesaid alkyl groups optionally being substituted by a substituent selected from halogen, amino, nitro, hydroxy and a C₅-C₆ cyclic group, and optionally wherein said 5 to 13-membered cyclic group is aromatic or heteroaromatic.

8. A compound of claim 5 wherein X is R⁶—

(CH₂)_p—

C(O)—

or R⁶—

(CH₂)_p—

O—

C(O)— and

p is 0 or 1.

9. A compound of claim 1 wherein the boronic acid is Cbz-(R)-Phe-(S)-Pro-(R)-Mpg-B(OH)₂.

15. A compound of claim 14 wherein the boronic acid is a compound of claim 1 wherein the boronic acid is Cbz-(R)-Phe-(S)-Pro-(R)-Mpg-B(OH)₂.

17. A compound of claim 15 which has a purity measured as HPLC peak area of at least 97.5%, the % peak area being determined by the method of Example 43.

18. A compound of claim 17 wherein the purity is at least 99%.

20. A compound of claim 5 in which R¹ is a group of the formula —

(CH₂)_s-Z wherein Z is —

OMe or —

OEt and which is free of any compound which is of the same structure except for replacement of the R¹ group by a group of the formula —

(CH₂)_s—

H.

10. A particulate composition comprising an isolated compound selected from boronic acids of formula (IIIa):

11. A compound selected from boronic acids of formula (IIIa):

12. A compound of claim 11 which has a decrease in weight upon drying of less than 0.5% of its initial weight when dried in a vacuum drier at 40°

C. at 100 mbar for 2 hours.

13. A compound of claim 11 wherein the boronic acid is of formula (VIII):

X-(R)-Phe-(S)-Pro-(R)-Mpg-B(OH)₂ 

 

(VIII).

14. A compound of claim 11 wherein

X is R⁶—

(CH₂)_p—

C(O)—

, R⁶—

(CH₂)_p—

S(O)₂—

, R⁶—

(CH₂)_p—

NH—

C(O)—

or R⁶—

(CH₂)_p—

O—

C(O)—

wherein p is 0, 1, 2, 3, 4, 5 or 6 and R⁶ is H or a 5 to 13-membered cyclic group optionally substituted by 1, 2 or 3 substituents selected from halogen, amino, nitro, hydroxy, a C₅-C₆ cyclic group, a C₁-C₄ alkyl group, a C₁-C₄ alkyl group containing an in-chain O, a C₁-C₄ alkyl group containing an in-chain O and linked to the cyclic group through an in-chain O and a C₁-C₄ alkyl group linked to the cyclic group through an in-chain 0, the aforesaid alkyl groups optionally being substituted by a substituent selected from halogen, amino, nitro, hydroxy and a C₅-C₆ cyclic group, and optionally said 5 to 13-membered cyclic group is aromatic or heteroaromatic;

aa¹ is selected from Phe, Dpa and wholly or partially hydrogenated analogues thereof;

aa² is a residue of an imino acid of formula (IV)

where R¹¹ is —

CH₂—

, —

CH₂—

CH₂—

, —

S—

CH₂—

, —

S—

C(CH₃)₂—

or —

CH₂—

CH₂—

CH₂—

, which group, when the ring is 5- or 6-membered, is optionally substituted at one or more —

CH₂—

groups by from 1 to 3 C₁-C₃ alkyl groups;

R¹ is 2-bromoethyl, 2-chloroethyl, 2-methoxyethyl, 3-bromopropyl, 3-chloropropyl or 3-methoxypropyl and wherein the (R,S,R) isomer is in a diastereomeric excess of 99% or more over the (R,S,S) isomer.

16. A compound of claim 11 which is substantially free of degradation product derived from cleavage of the C—

B bond thereof.

19. Cbz-(R)-Phe-(S)-Pro-(R)-Mpg-B(OH)₂ when substantially free of the compound:

21. Cbz-(R)-Phe-(S)-Pro-(R)-Mpg-B(OH)₂ when substantially free of the compound:

22. Cbz-(R)-Phe-(S)-Pro-(R)-Mpg-B(OH)₂ when in a diastereomeric excess of at least 99% over the (R,S,S) diastereomer, substantially free of the compound:

23. A product comprising isolated, dry Cbz-(R)-Phe-(S)-Pro-(R)-Mpg-B(OH)₂ in a diastereomeric excess of 99% or more over its (R,S,S) diastereomer.

24. A product of claim 23 which is sterile and otherwise adapted to be pharmaceutically acceptable.

25. A process for making a pharmaceutically acceptable base addition salt of a boronic acid of formula (IIIa):

26. The process of claim 25 wherein the salt is a metal salt

27. The process of claim 25 wherein the salt is a salt of an alkali metal, an alkaline earth metal or zinc.

28. The process of claim 25 wherein the base is an organic base having a pKb of 7 or more.

59. A process for making a pharmaceutical formulation, comprising performing the process of claim 25 and formulating the product salt into a pharmaceutical formulation.

29. A process for making a pharmaceutically acceptable base addition salt of an organoboronic acid inhibitor of thrombin having a neutral thrombin S1-binding moiety linked through a peptide linkage to a hydrophobic thrombin S2/S3-binding moiety, comprising combining a solution of the organoboronic add in a water-miscible organic solvent with an aqueous solution or suspension of the base, causing or allowing the acid and the base to react, and recovering the salt.

30. A process of claim 29 in which the base comprises a cation of valency n and is used in a stoichiometry (boronic acid:

base) of about n;

1.

31. A process of claim 30 in which the base is a metal base.

32. A process of claim 31 in which the base is an alkali metal or alkaline earth metal base, or a zinc base.

33. A process of claim 30 in which the base is an organic nitrogen-containing compound having a pKb of about 7 or more.

34. A process of claim 29 wherein the solvent is acetonitrile.

35. A process of claim 34 wherein the recovery of the salt comprises evaporating to dryness to obtain an evaporation residue and the process further comprises:

redissolving the evaporation residue in acetonitrile and evaporating the resulting solution to dryness; and

repeating the redissolution and evaporation steps as often as necessary to obtain a substantially dry evaporation residue.

36. A process of claim 35 which further comprises:

dissolving the dry evaporation residue in acetonitrile or tetrahydrofuran to form a solution;

adding, at a rate sufficiently slow to avoid lump formation, said solution to a 3;

1 to 1;

3 v/v mixture of diethylether and an aliphatic or cycloaliphatic solvent to form a precipitate, said solution being added to the diethylether/(cyclo)aliphatic solvent mixture in a ratio (solution;

mixture) of from 1;

5 to 1;

15 v/v;

recovering the precipitate; and

removing solvent from the recovered precipitate under reduced pressure whilst maintaining the temperature at no more than 35°

C.

37. A process of claim 36 in which the aliphatic or cycloaliphatic solvent is n-heptane.

38. A process of claim 34 in which the base is sodium hydroxide.

39. A process of claim 36 in which the base is sodium hydroxide and the dry evaporation residue is dissolved in acetonitrile.

40. A process of claim 34 in which the base is calcium hydroxide.

41. A process of claim 36 in which the base is calcium hydroxide and the dry evaporation residue is dissolved in tetrahydrofuran.

42. A process of claim 29 wherein the solvent is tetrahydrofuran or an alcohol.

43. A process claim 29 wherein the solvent is dry.

44. A process of claim 29 wherein the boronic acid is of formula (I):

45. A process of claim 44 wherein R⁹ is an alkoxyalkyl group and Y is an optionally N-terminally protected dipeptide which binds to the S3 and S2 binding sites of thrombin and the peptide linkages in the acid are optionally and independently N-substituted by a C₁-C₁₃ hydrocarbyl optionally containing in-chain or in-ring nitrogen, oxygen or sulfur and optionally substituted by a substituent selected from halo, hydroxy and trifluoromethyl, and optionally wherein said dipeptide is N-terminally protected, all the peptide linkages in the acid are unsubstituted or the dipeptide is N-terminally protected and all the peptide linkages in the acid are unsubstituted.

46. A process of claim 45 wherein the S3-binding amino acid residue is of (R)-configuration, the S2-binding residue is of (S)-configuration, and the fragment —

NHCH(R⁹)—

B(OH) is of (R)-configuration.

47. A process of claim 29 wherein the boronic acid is of formula (II):

48. A process of claim 47 wherein

X is R⁶—

(CH₂)_p—

C(O)—

, R⁶—

(CH₂)_p—

S(O)₂—

, R⁶—

(CH₂)_p—

NH—

C(O)—

or R⁶—

(CH₂)_p—

O—

C(O)—

wherein p is 0, 1, 2, 3, 4, 5 or 6 and R⁶ is H or a 5 to 13-membered cyclic group optionally substituted by 1, 2 or 3 substituents selected from halogen, amino, nitro, hydroxy, a C₅-C₆ cyclic group, a C₁-C₄ alkyl group, a C₁-C₄ alkyl group containing an in-chain 0, a C₁-C₄ alkyl group containing an in-chain 0 and linked to the cyclic group through an in-chain 0 and a C₁-C₄ alkyl group linked to the cyclic group through an in-chain O, the aforesaid alkyl groups optionally being substituted by a substituent selected from halogen, amino, nitro, hydroxy and a C₅-C₆ cyclic group, and optionally said 5 to 13-membered cyclic group is aromatic or heteroaromatic, e.g. is phenyl or a 6-membered heteroaromatic group, for example X is benzyloxycarbonyl;

aa¹ is selected from Phe, Dpa and wholly or partially hydrogenated analogues thereof, and optionally is selected from Dpa, Phe, Dcha and Cha;

aa² is a residue of an imino acid of formula (IV)

where R¹¹ is —

CH₂—

, —

CH₂—

CH₂—

, —

S—

CH₂—

, —

S—

C(CH₃)₂—

or —

CH₂—

CH₂—

CH₂—

, which group, when the ring is 5- or 6-membered, is optionally substituted at one or more —

CH₂—

groups by from 1 to 3 C₁-C₃ alkyl groups;

R¹ is 2-bromoethyl, 2-chloroethyl, 2-methoxyethyl, 3-bromopropyl, 3-chloropropyl or 3-methoxypropyl; and

aa¹ is of (R)-configuration, aa² is of (S)-configuration and the fragment —

NH—

CH(R¹)—

B(OH)₂ is of (R)-configuration.

49. A process of claim 29 wherein the boronic acid is of formula (VIII):

X-(R)-Phe-(S)-Pro-(R)-Mpg-B(OH)₂ 

 

(VIII).

50. A solution whose solvent is a water-miscible organic solvent and which contains species selected from an organoboronic add inhibitor of thrombin having a neutral thrombin S1-binding moiety linked through a peptide linkage to a hydrophobic thrombin S2/S3-binding moiety, and equilibrium forms of the organoboronic acid.

51. A solution of claim 50 wherein the solvent is acetonitrile.

52. A solution of claim 50 wherein the solvent is an alcohol or tetrahydrofuran.

53. A solution of claim 50 having the characteristics of a solution obtained by dissolving the free organoboronic acid in the solvent.

54. A solution of claim 50 which consists essentially of the solvent, the organoboronic acid dissolved in the solvent and any species in equilibrium with the organoboronic acid.

55. A solution of claim 50 wherein the organoboronic acid is of formula (I):

56. A solution of claim 50 wherein the boronic acid is of formula (II):

57. A solution of claim 50 wherein the acid is Cbz-(R)-Phe-(S)-Pro-(R)-Mpg-B(OH)₂ and the solvent is acetonitrile.

58. A solution of claim 50 wherein the acid is Cbz-(R)-Phe-(S)-Pro-(R)-Mpg-B(OH)₂ and the solvent is tetrahydrofuran or an alcohol.