Process for the preparation of acalabrutinib
The present invention provides processes for the preparation of Acalabrutinib (1), as well as intermediates useful in the preparation thereof. In particular, processes are provided for coupling of a compound of Formula (5) and 2-butynoic acid in the presence of Carbodiimide (8) to afford Acalabrutinib (1).
1. A process for the preparation of Acalabrutinib (1):
comprising:
(i) treating a compound of Formula (7):
with a carbodiimide selected from the group consisting of:
optionally in the presence of Additive (A-H):
A-H,
wherein:
A is selected from the group consisting of:
wherein:
(a) R a is H; and
R b is H; or
(b) R a is R c ; and
R b is R d ;
R c and R d , taken together with the carbon atoms to which they are bonded, form a C 3-12 cycloaliphatic, C 6-10 aryl, or C 5-9 heteroaryl, wherein the C 3-12 cycloaliphatic, C 6-10 aryl, and C 5-9 heteroaryl are each optionally substituted with nitro, and further wherein the C 5-9 heteroaryl has at least one heteroatom selected from the group consisting of nitrogen, oxygen, and sulfur; and
R 3 is C 6-10 aryl, optionally substituted with nitro;
to provide an activated acid derivative selected from the group consisting of (a) and (b):
(a)
and
(b) a compound of Formula (4):
wherein:
A is selected from the group consisting of:
wherein:
(a) R a is H; and
R b is H; or
(b) R a is R c ; and
R b is R d ;
R c and R d , taken together with the carbon atoms to which they are bonded, form a C 3-12 cycloaliphatic, C 6-10 aryl, or C 5-9 heteroaryl, wherein the C 3-12 cycloaliphatic, C 6-10 aryl, and C 5-9 heteroaryl are each optionally substituted with nitro, and further wherein the C 5-9 heteroaryl has at least one heteroatom selected from the group consisting of nitrogen, oxygen, and sulfur; and
R 3 is C 6-10 aryl, optionally substituted with nitro; and
(ii) coupling the activated acid derivative formed in step (i) above with a compound of Formula (5):
wherein:
G 1 is
2. The process of claim 1 , wherein the carbodiimide is selected from the group consisting of:
3. The process of claim 1 , wherein the compound of Formula (7) is treated with a carbodiimide in the presence of Additive (A-H) to provide the activated acid derivative.
4. The process of claim 3 , wherein:
R c and R d , taken together with the carbon atoms to which they are bonded, form a phenyl, optionally substituted with nitro; and
R 3 is phenyl, optionally substituted with nitro.
5. The process of claim 3 , wherein Additive (A-H) is selected from the group consisting of:
6. The process of claim 3 , wherein the activated acid derivative is a compound of Formula (4):
7. The process of claim 6 , wherein A is selected from the group consisting of:
8. The process of claim 6 , wherein the activated acid derivative is the compound of Formula (4-A):
9. The process of claim 6 , wherein the activated acid derivative is isolated prior to step (ii).
10. The process of claim 3 , wherein step (i) is completed prior to performing step (ii).