Derivatives of 4,5,6,7-tetrabromobenzimidazole and method of their preparation

1. A derivative of 4,5,6,7-tetrabromobenzimidazole of Formula 1

wherein

R 1 is a hydrogen or an aliphatic group; and

R 2 is an aliphatic group, optionally substituted with a substituent selected from a hydroxyl and a substituted amino group.

2. The derivative according to claim 1 , which is 2-methylamino-4,5,6,7-tetrabromo-1H-benzimidazole.

3. The derivative according to claim 1 , which is 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole.

4. The derivative according to claim 1 , which is 2-ethanolamino-4,5,6,7-tetrabromo-1H-benzimidazole.

5. The derivative according to claim 1 , which is 2-isopropylamino-4,5,6,7-tetrabromo-1H-benzimidazole.

6. The derivative according to claim 1 , which is 2-(2-hydroxypropylamino)-4,5,6,7-tetrabromo-1H-benzimidazole.

7. The derivative according to claim 1 , which is 2-(2-dimethylaminoethylamino)-4,5,6,7-tetrabromo-1H-benzimidazole.

8. A method of preparation of a derivative of 4,5,6,7-tetrabromobenzimidazole of Formula 1

comprising

(a) reacting a compound of Formula 2

with an amine at an elevated temperature; and

(b) purifying the resulting product by crystallization or silica gel chromatography

wherein

R 1 is a hydrogen or an aliphatic group;

R 2 is an aliphatic group, optionally substituted with a substituent selected from a hydroxyl and a substituted amino group; and

R 3 is a halogen, an alkylthio, an alkoxy, a sulfone or an alkylsulfoxide.

9. The method of claim 8 , wherein R 3 is selected from the group —Cl, —Br, CH 3 S—, C 2 H 5 S—, C 3 H 7 S—, CH 3 O, and C 2 H 5 O—.

10. The method according to claim 8 wherein said amine is a primary lower aliphatic amine.

11. The method according to claim 10 wherein said primary aliphatic amine includes in the aliphatic chain additionally hydroxyl groups or substituted amino groups.

12. The method according to claim 8 wherein said amine is a secondary lower aliphatic amine.

13. The method according to claim 8 wherein said amine is used both as a reagent and as a co-solvent in an aqueous or alcoholic solution.

14. The method according to claim 8 wherein the reaction of said compound of Formula 2 with said amine is carried out at a temperature in the range between 80 to 140° C.

15. A pharmaceutical composition exhibiting an anti-leukemic activity comprising a pharmaceutically-effective amount of a derivative of 4,5,6,7-tetrabromobenzimidazole of Formula 1

and at least one inert, pharmaceutically acceptable carrier or diluent wherein

R 1 is a hydrogen or an aliphatic group; and

R 2 is an aliphatic group, optionally substituted with a substituent selected from a hydroxyl and a substituted amino group.

16. The pharmaceutical composition of claim 15 , wherein said derivative of 4,5,6,7-tetrabromobenzimidazole of Formula 1 is selected from the group consisting of 2-methylamino-4,5,6,7-tetrabromo-1H-benzimidazole; 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole; 2-ethanolamino-4,5,6,7-tetrabromo-1H-benzimidazole; 2-isopropylamino-4,5,6,7-tetrabromo-1H-benzimidazole; and 2-isopropylamino-4,5,6,7-tetrabromo-1H-benzimidazole; 2-(2-hydroxypropylamino)-4,5,6,7-tetrabromo-1H-benzimidazole; and 2-(2-dimethylaminoethylamino)-4,5,6,7-tetrabromo-1H-benzimidazole.

17. A method of inhibiting caseine kinase 2 activity in a patient in the need of such treatment whereby human leukemia is treated, comprising administering to said patient a pharmaceutically-effective amount of the compound of Formula 1

wherein

R 1 is a hydrogen or an aliphatic group; and

R 2 is an aliphatic group, optionally substituted with a substituent selected from a hydroxyl and a substituted amino group.

18. The method of claim 17 , wherein said compound of Formula 1 is selected from the group consisting of 2-methylamino-4,5,6,7-tetrabromo-1H-benzimidazole; 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole; 2-ethanolamino-4,5,6,7-tetrabromo-1H-benzimidazole; 2-isopropylamino-4,5,6,7-tetrabromo-1H-benzimidazole; and 2-isopropylamino-4,5,6,7-tetrabromo-1H-benzimidazole; 2-(2-hydroxypropylamino)-4,5,6,7-tetrabromo-1H-benzimidazole; and 2-(2-dimethylaminoethylamino)-4,5,6,7-tetrabromo-1H-benzimidazole.

19. A method of treating human leukemia in a patient in the need of such treatment comprising administering to said patient a pharmaceutically-effective amount of the compound of Formula 1

wherein

R 1 is a hydrogen or an aliphatic group; and

R 2 is an aliphatic group, optionally substituted with a substituent selected from a hydroxyl and a substituted amino group.

20. The method of claim 19 , wherein said compound of Formula 1 is selected from the group consisting of 2-methylamino-4,5,6,7-tetrabromo-1H-benzimidazole; 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole; 2-ethanolamino-4,5,6,7-tetrabromo-1H-benzimidazole; 2-isopropylamino-4,5,6,7-tetrabromo-1H-benzimidazole; and 2-isopropylamino-4,5,6,7-tetrabromo-1H-benzimidazole; 2-(2-hydroxypropylamino)-4,5,6,7-tetrabromo-1H-benzimidazole; and 2-(2-dimethylaminoethylamino)-4,5,6,7-tetrabromo-1H-benzimidazole.