Anti-mitotic anti-proliferative compounds

1. A compound of Formula I:

wherein

Het is a substituted 1,2,4-triazole;

Z 1 , Z 2 , and Z 3 are independently a bond or R 1 —X—R 2 , wherein X is NR 3 , O, S, SO, or SO 2 ;

R 1 and R 2 are independently a bond or substituted or unsubstituted, saturated or unsaturated, straight-chained or branched lower alkylene; and R 3 is hydrogen, substituted or unsubstituted phenyl, or substituted or unsubstituted, saturated or unsaturated, straight-chained or branched lower alkyl;

Ar 1 is substituted monocyclic aryl;

Ar 2 is substituted or unsubstituted indolyl;

R a is hydrogen or a substituted or unsubstituted monocyclic, aryl, or heteroaryl ring system of 5 or 6 ring atoms or a bicyclic aryl or heteroaryl ring system of 8 to 12 ring atoms, wherein each monocyclic ring may contain 0 to 3 heteroatoms, each bicyclic ring may contain 0 to 4 heteroatoms, and each heteroatom is independently selected from the group consisting of N, O, and S; and

the substituents of Ar 1 , Ar 2 , and R a , when substituted, comprise one to three moieties independently selected from the group consisting of alkyl, alkenyl, alkynyl, phenyl, aralkyl, aralkenyl, hydroxy, hydroxyalkyl, alkoxy, alkoxyalkyl, aralkoxy, aryloxy, acyloxy, halo, haloalkyl, nitro, cyano, amino, mono- and dialkylamino, acylamino, carboxy, carboxyalkyl, carbalkoxy, carbaralkoxy, carbalkoxyalkyl, carbalkoxyalkenyl, aminoalkoxy, amido, mono-alkylamido , di-alkylamido, N,N-cycloaLkylamido, sulfonyl, mono-alkyl sulfonyl, di-alkyl sulfonyl, sulfamoyl, monoalkyl sulfamoyl, di-alkyl sulfamoyl, halophenyl, benzoyl, alkylthio and alkylsulfmyl; or

a pharmaceutically acceptable salt thereof.

2. The compound of claim 1 , wherein Ar 1 is substituted benzene, and Ar 2 is substituted or unsubstituted.

3. The compound of claim 1 , wherein R a is a substituted or unsubstituted aromatic ring selected from the group consisting of benzene, pyrrole, thiophene, furan, thiazole, imidazole, pyrazole, 1,2,4-triazole, pyridine, 2(1H)-pyridone, 4(1H)pyridone, pyrazine, pyrimidine, pyridazine, isothiazole, isoxazole, oxazole, tetrazole, naphthalene, tetralin, naphthyridine, benzofuran, benzothiophenc, indole, 2,3dihydroindole, 1H-indazole, indoline, benzopyrazole, 1,3-benzodioxole , benzoxazole, purine, coumarin, chromone, quinoline, tetrahydroquinoline, isoquinoline, benzimidazole, quinazoline, pyrido[2,3-b]pyrazine, pyrido[3,4-b]pyrazine, pyrido[3,2-c ]pyridazine, pyrido[3,4-b]-pyridine, 1H-pyrazole[3,4-d]pyrimidine, pteridine, 2(1H)-quinolone, 1(2H)-isoquinolone, 1,4-benzisoxazine, benzothiazole, quinoxaline, quinoline-N-oxide, isoquinoline-N-oxide, quinoxaline-N-oxide, quinazoline-N-oxide, benzoxazine, phthalazine and cinnoline.

4. The compound of claim 1 , wherein each of Z 1 , Z 2 , and Z 3 is a bond; Ar 1 is a substituted benzene; and R a is hydrogen.

5. The compound of claim 4 , wherein Ar 1 is substituted with 1 to 3 alkoxy groups.

6. The compound of claim 4 , wherein Ar 1 is substituted with 1 to 3 alkoxy groups and Ar 2 is substituted with 1 to 3 substituents independently selected from hydroxyl, amino, and monoalkylamino groups.

7. The compound of claim 1 having the formula:

8. The compound of claim 1 having the formula:

9. A pharmaceutical composition comprising a pharmaceutically effective amount of the compound according to claim 1 and a pharmaceutically acceptable carrier.

10. The compound of claim 1 , wherein Z 1 , Z 2 , and Z 3 are each independently a bond, further characterized by formula:

wherein R is hydrogen, hydroxyl, amino, or monoalkylamino.

11. The compound of claim 10 , wherein R is hydrogen.

12. The compound of claim 1 , wherein Z 1 , Z 2 , and Z 3 are each independently a bond, further characterized by formula:

wherein R is hydrogen, hydroxyl, amino, or monoalkylamino.

13. The compound of claim 12 , wherein R is hydrogen.

14. The compound of claim 1 , wherein Z 1 , Z 2 , and Z 3 are each independently a bond, further characterized by formula:

wherein R 1 and R 2 are independently selected from the group consisting of hydrogen, —OH, —NH 2 , —OCH 3 , —N(CH 3 ) 2 , —CH 2 OH, —CH 2 OCH 3 , and —CH 2 N(CH 3 ) 2 ,