Methods for the preparation of charged crosslinkers
Processes for the preparation of charged crosslinkers bearing a sulfonic acid moiety are disclosed. These procedures also optionally include methods to convert the resulting products to substantially a single salt form.
1. A process for the preparation of a compound of formula (III):
or a salt thereof, comprising the step of reacting a compound of formula (II):
or a salt thereof, with a sulfonating agent, wherein:
Q represents a thiol-reactive moiety;
E represents a linear, branched or cyclic alkyl, alkenyl or alkynyl bearing 1 to 10 carbon atoms, a phenyl group, a three to six membered heterocycloalkyl group or a five or six-membered heteroaromatic group, containing 1, 2 or 3 heteroatoms selected from O, N or S;
F is an optional moiety that has the same definition as E; or when G is absent, F and R 1 together with the carbon atom from which they are attached can form a three to seven membered cycloalkyl group;
G is absent or represents -G′-(OCH 2 CH 2 ) n —, -G′-(CH 2 —CH 2 —O) n — or -(AA) m -;
G′ is absent, —C(═O)—NH— or —NH—C(═O)—,
AA represents an amino acid residue;
R 1 is —H or a linear, branched or cyclic alkyl, alkenyl or alkynyl bearing 1 to 10 carbon atoms;
n is 0 or an integer from 1 to 24; and
m is 0 or an integer from 1 to 6.
2. The process of claim 1 , wherein the sulfonating agent is chlorosulfonic acid or sulfur trioxide.
3. The process of claim 1 , wherein the sulfonating agent is chlorosulfonic acid.
4. The process of any one of claims 1 - 3 , wherein the sulfonating reaction is carried out in the presence of a base.
5. The process of claim 4 , wherein the base is triethyl amine, diisopropylethyl amine or tributyl amine.
6. The process of claim 5 , wherein the base is diisopropylethyl amine.
7. The process of claim 1 , wherein the process further comprises the step of purifying the compound of formula (III) obtained by the reaction.
8. The process of claim 7 , wherein the compound of formula (III) is purified by reverse phase chromatography.
9. The process of claim 1 , wherein G and F are both absent, E is a linear or branched alkyl bearing 1 to 4 carbon atoms.
10. The process of claim 9 , wherein E is —CH 2 —CH 2 —.
11. The process of claim 1 , wherein G is absent, and F and R 1 together with the carbon atom from which they are attached form a cyclohexyl group.
12. The process of claim 11 , wherein E is a linear or branched alkyl bearing 1 to 4 carbon atoms.
13. The process of claim 12 , wherein E is —CH 2 —.
14. The process of claim 1 , wherein Q is a disulfide group selected from alkyl disulfide, phenyl disulfide, ortho or para-nitrophenyl disulfide, 2,4-dintrophenyl disulfide, pyridyl disulfide, nitropyridyl disulfide; a maleimido group or a haloacetyl group.
15. The process of claim 14 , wherein Q is pyridyl disulfide or maleimido group.
16. The process of claim 14 , wherein Q is pyridyl disulfide.
17. The process of claim 1 , wherein the compound of formula (III) or a salt thereof is a compound of formula (IV):
or a salt thereof, and wherein the compound of formula (II) or a salt thereof is a compound of formula (2a):
or a salt thereof.
18. The process of claim 17 , wherein the sulfonating agent is chlorosulfonic acid or sulfur trioxide.
19. The process of claim 17 , wherein the sulfonating agent is chlorosulfonic acid.
20. The process of claim 17 , wherein the sulfonating reaction is carried out in the presence of 1,2-di(pyridin-2-yl)disulfane (PySSPy).
21. The process of claim 20 , wherein about 0.5 equivalent of PySSPy is present.
22. The process of claim 17 , wherein the process further comprises the step of purifying the compound of formula (IV) obtained by the reaction.
23. The process of claim 22 , wherein the compound of formula (IV) is purified by reverse phase chromatography.
24. The process of claim 22 , wherein the compound of formula (IV) is purified by using a silica column.
25. The process of claim 1 , further comprising
reacting the compound of formula (III) or a salt thereof, with a hydroxy or mercapto compound to form a compound of formula (I),
or a salt thereof, wherein C(═O)L represents a reactive ester or thioester group.
26. The process of claim 25 , wherein the sulfonating agent is chlorosulfonic acid or sulfur trioxide.
27. The process of claim 25 , wherein the sulfonating agent is chlorosulfonic acid.
28. The process of claim 25 , wherein the reaction between the compound of formula (III) and the hydroxy or mercapto compound is carried out in the presence of a coupling agent.
29. The process of claim 28 , wherein the coupling agent is selected from N,N′-dicyclohexylcarbodiimide (DCC), 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC), N,N′-diisopropyl carbodiimide (DIC) and 1-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ).
30. The process of claim 29 , wherein the coupling agent is EDC.
31. The process of claim 25 , wherein the reactive ester or thioester group is selected from N-hydroxysuccinimide ester, N-hydroxy sulfosuccinimide ester, nitrophenyl ester, tetrafluoro phenyl ester, pentafluorophenyl ester, a thiopyridyl ester and a thionitrophenyl ester.
32. The process of claim 31 , wherein the reactive ester is N-hydroxysuccinimide ester.
33. The process of claim 25 , further comprising the step of purifying the compound of formula (III) or a salt thereof.
34. The process of claim 33 , wherein the compound of formula (III) or a salt thereof is purified by reverse phase chromatography.
35. The process of claim 25 , further comprising the step of purifying the compound of formula (I).
36. The process of claim 35 , wherein the compound of formula (I) is purified by reverse phase chromatography.
37. The process of claim 25 , wherein G and F are both absent, E is a linear or branched alkyl bearing 1 to 4 carbon atoms.
38. The process of claim 37 , wherein E is —CH 2 —CH 2 —.
39. The process of claim 25 , wherein G is absent, and F and R 1 together with the carbon atom from which they are attached form a cyclohexyl group.
40. The process of claim 39 , wherein E is a linear or branched alkyl bearing 1 to 4 carbon atoms.
41. The process of claim 40 , wherein E is —CH 2 —.
42. The process of claim 25 , wherein Q is a disulfide group selected from alkyl disulfide, phenyl disulfide, ortho or para-nitrophenyl disulfide, 2,4-dintrophenyl disulfide, pyridyl disulfide, nitropyridyl disulfide; a maleimido group or a haloacetyl group.
43. The process of claim 42 , wherein Q is pyridyl disulfide or maleimido group.
44. The process of claim 42 , wherein Q is pyridyl disulfide.
45. The process of claim 17 , further comprising preparation of a compound represented by formula (V):
reacting the compound of formula (IV) or a salt thereof, with N-hydroxysuccinimide to form the compound of formula (V),
or a salt thereof.
46. The process of claim 45 , wherein the sulfonating agent is chlorosulfonic acid or sulfur trioxide.
47. The process of claim 45 , wherein the sulfonating agent is chlorosulfonic acid.
48. The process of claim 45 , wherein the sulfonating reaction is carried out in the presence of PySSPy.
49. The process of claim 48 , wherein about 0.5 equivalent of PySSPy is present.
50. The process of claim 45 , wherein the reaction between the compound of formula (IV) and N-hydroxysuccinimide is carried out in the presence of a coupling agent.
51. The process of claim 50 , wherein the coupling agent is selected from N,N′-dicyclohexylcarbodiimide (DCC), 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC), N,N′-diisopropyl carbodiimide (DIC) and 1-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ).
52. The process of claim 51 , wherein the coupling agent is EDC.
53. The process of claim 45 , wherein the reaction between the compound of formula (IV) and N-hydroxysuccinimide is carried in the presence of a base.
54. The process of claim 53 , wherein the base is diisopropylethylamine (DIPEA).
55. The process of claim 45 , wherein the process comprises the steps of:
a) reacting the compound of formula (2a) or a salt thereof with chlorosulfonic acid to form the compound of formula (IV); and
b) reacting the compound of formula (IV) with N-hydroxysuccinimide in the presence of EDC to form the compound of formula (V).
56. The process of claim 45 , further comprising the step of purifying the compound of formula (IV) or a salt thereof.
57. The process of claim 56 , wherein the compound of formula (IV) or a salt thereof is purified by reverse phase chromatography.
58. The process of claim 56 , wherein the compound of formula (IV) or a salt thereof is purified by using a silica column.
59. The process of claim 45 , further comprising the step of purifying the compound of formula (V) or a salt thereof.
60. The process of claim 59 , wherein the compound of formula (V) or a salt thereof is purified by reverse phase chromatography.
61. The process of claim 59 , wherein the compound of formula (V) or a salt thereof is purified by using a silica column.
62. The process of claim 59 , wherein the compound of formula (V) or a salt thereof is purified by crystallization.