Antiproliferative pyrimidine-based compounds

1. A compound selected from:

or a pharmaceutically acceptable salt thereof;

wherein:

X 1 , X 2 , X 3 , and X 4 are independently CH, CR 6 , and N; and wherein at most 3 of X 1 ,

X 2 , X 3 ,

and X 4 are N;

w is 0 or 1;

y is 0, 1, 2, 3, or 4;

is either a single or double bond;

R is hydrogen, C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 3 -C 6 alkynyl, —(C 0 -C 2 alkyl)(C 3 -C 8 carbocyclyl), —(C 0 -C 2 alkyl)(C 3 -C 8 heterocyclyl), —(C 0 -C 2 alkyl)(aryl), —(C 0 -C 2 alkyl)(heteroaryl), -COOalkyl, —COOarylalkyl, or COOH;

each R 1 is independently alkyl, aryl, cycloalkyl and haloalkyl, wherein each of said alkyl, cycloalkyl and haloalkyl groups optionally includes heteroatoms O, N, or S in place of a carbon in the chain and two R 1 's on adjacent ring atoms or on the same ring atom together with the ring atom(s) to which they are attached optionally form a saturated 3-8-membered cycle;

R 2 is (alkylene) m -heterocyclo, -(alkylene) m -heteroaryl, -(alkylene) m -NR 3 R 4 , -(alkylene) m -C(O)—NR 3 R 4 ; -(alkylene) m -C(O)—O-alkyl; -(alkylene) m -O—R 5 , -(alkylene) m -S(O) n —R 5 , or -(alkylene) m -S(O) n —NR 3 R 4 ; any of which may be optionally independently substituted with one or more R′ groups as allowed by valance, and wherein two R′ groups bound to the same or adjacent atom may optionally combine to form a ring;

m is 0, 1, or 2;

n is 0, 1, or 2;

R 3 and R 4 at each occurrence are independently selected from hydrogen, alkyl, cycloalkyl, heterocyclo, aryl, heteroaryl, cycloalkylalkyl, heterocycloalkyl, arylalkyl, and heteroarylalkyl; or R 3 and R 4 together with the nitrogen atom to which they are attached may combine to form a heterocyclo;

R 5 is independently selected at each occurrence from hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, heterocyclo, aryl, heteroaryl, cycloalkylalkyl, heterocycloalkyl, arylalkyl, and heteroarylalkyl;

R x at each occurrence is independently selected from halo, cyano, nitro, oxo, alkyl, haloalkyl, alkenyl, alkynyl, cycloalkyl, heterocyclo, aryl, heteroaryl, arylalkyl, heteroarylalkyl, cycloalkylalkyl, heterocycloalkyl, -(alkylene) m -OR 5 , -(alkylene) m -O-alkylene-OR 5 , -(alkylene) m -S(O) n —R 5 , -(alkylene) m -NR 3 R 4 , -(alkylene) m -CN, -(alkylene) m -C(O)—R 5 , -(alkylene) m -C(S)—R 5 , -(alkylene) m -C(O)—OR 5 , -(alkylene) m -O—C(O)—R 5 , -(alkylene) m -C(S)—OR 5 , -(alkylene) m -C(O)-(alkylene) m -NR 3 R 4 , -(alkylene) m -C(S)—NR 3 R 4 , -(alkylene) m -N(R 3 )—C(O)—NR 3 R 4 , -(alkylene) m -N(R 3 )—C(S)—NR 3 R 4 , -(alkylene) m -N(R 3 )—C(O)—R 5 , -(alkylene) m -N(R 3 )—C(S)—R 5 , -(alkylene) m -O—C(O)—NR 3 R 4 , -(alkylene) m -O—C(S)—NR 3 R 4 , -(alkylene) m -SO 2 —NR 3 R 4 , -(alkylene) m -N(R 3 )—SO 2 —R 5 , -(alkylene) m -N(R 3 )—SO 2 —NR 3 R 4 , -(alkylene) m -N(R 3 )—C(O)—OR 5 ) -(alkylene) m -N(R 3 )—C(S)—OR 5 , and -(alkylene) m -N(R 3 )—SO 2 —R 5 ;

R 6 is selected independently at each instance from: hydrogen, halogen, alkyl, alkenyl, alkynyl, cycloalkyl, heterocyclo, aryl, heteroaryl, cycloalkylalkyl, heterocycloalkyl, arylalkyl, and heteroarylalkyl;

R 7 is selected from:

Y is NH, O, S, or NR 9 ;

X 5 , X 6 , X 7 are independently N or CR 8 , wherein at least one of X 5 , X 6 , and X 7 is CR 8 ;

R 8 is selected independently at each instance from: R 6 and R 2 , wherein one R 8 is R 2 ; and

R 9 is selected from: —C(O)H, —C(O)alkyl, —C(S)alkyl, alkyl, aryl, heteroaryl, arylalkyl, and heteroarylalkyl.

2. The compound of claim 1 , wherein y is 0.

3. The compound of claim 1 , wherein y is 1.

4. The compound of claim 1 , wherein y is 2.

5. The compound of claim 4 , wherein two R 1 groups on adjacent ring atoms or on the same ring atom together with the ring atom(s) to which they are attached optionally form a 3-8-membered cycle.

6. The compound of claim 5 , wherein the 3-8-membered cycle is a 6-membered cycle.

7. The compound of claim 6 wherein R 2 is:

8. The compound of claim 1 , wherein R 2 is heterocyclo optionally independently substituted with one or more R x groups as allowed by valance.

9. The compound of claim 8 , wherein R x at each occurrence is independently selected from halo, cyano, nitro, oxo, alkyl, haloalkyl, alkenyl, alkynyl, cycloalkyl, heterocyclo, aryl, heteroaryl, arylalkyl, heteroarylalkyl, cycloalkylalkyl, and heterocycloalkyl.

10. The compound of claim 1 wherein R 2 is:

11. The compound of claim 1 , wherein m is 0.

12. The compound of claim 1 , wherein n is 0.

13. The compound of claim 1 , wherein R 3 and R 4 are hydrogen.

14. The compound of claim 1 , wherein R 5 is alkyl.

15. The compound of claim 1 , wherein R is hydrogen.

16. The compound of claim 15 , wherein R 2 is heterocyclo optionally independently substituted with one or more R x groups as allowed by valance.

17. The compound of claim 1 selected from:

or a pharmaceutically acceptable salt thereof.

18. The compound of claim 1 selected from:

or a pharmaceutically acceptable salt thereof.

19. A pharmaceutical composition comprising an effective amount of a compound of claim 1 and a pharmaceutically acceptable carrier.