Synthesis and in-vitro anticancer activity of 3-cyano-6,9-dimethyl-4-imino 2-methylthio 4H-pyrimido [2,1-b] [1,3] benzothiazole and its 2-substituted derivatives

Aim

Novel heterocycle 3-cyano 6,9-dimethyl 4-imino 2-methylthio 4H pyrimido [2,1-b] [1,3] benzothiazole 3 has been prepared by using 2-amino 4,7-dimethtyl benzothiazole 1 and bis-methylthio methylene malononitrile 2.

Method

Compound 3 prepared from 2-amino 4,7-dimethyl benzothiazole 1 was refluxed with bis-methylthio methylene malononitrile 2 in presence of anhydrous potassium carbonate and N,N-dimethyl formamide as solvent. Compound 3 possesses replaceable methylthio functionality at 2-postion, which was replaced by using selected different nucleophiles like phenols/aryl amines/heteryl amines and compounds containing active methylene group to afford 2-substituted derivatives 4–7 of compound 3.

Results

Heterocyclic compounds containing benzothiazoles fused with pyrimidines, pyrazoles reported to possess activity against the different types of cancers. Compound 3 and it's selected derivatives 4–7 were screened for their in-vitro anticancer activity towards 60 Human cancer cell lines at National Cancer Institute, Maryland USA. Many compounds exhibited remarkable activity against 60 human cell lines.

Conclusion

The compounds 3, 4-a, 4-d, 5-a, 6-a, 6-b exhibited maximum in-vitro anticancer activity against different cancers lines.