Synthesis of novel 1,2,3-triazole substituted-N-alkyl/aryl nitrone derivatives, their anti-inflammatory and anticancer activity.

A series of novel 1,2,3-triazole substituted N-phenyl nitrone derivatives 5a-e were prepared in three steps starting from 1-substituted-1,2,3-triazole-4-carbaldehydes 2 via Schiff's base formation, reduction followed by oxidation. Similarly, 1,2,3-triazole substituted N-alkyl nitrone derivatives 6a-p were prepared in single step starting from compound 2 on reaction with N-alkyl hydroxylamine hydrochlorides. All the final compounds were screened for anti-inflammatory and anticancer activity against various cancer cell lines. Among the compounds tested, the compounds 5a, 5d, 6a, 6b, 6m and 6o exhibited significant inhibition of IL-1ß secretion as a measure of anti-inflammatory activity. Compound 5b, 5c, 6h, 6i and 6o exhibited significant activity against all the cell lines (A549, COLO 205, MDA-MB 231 and PC-3) at IC50 values of <15 µM.

Synthesis of novel 5-(3-alkylquinolin-2-yl)-3-aryl isoxazole derivatives and their cytotoxic activity.

The propargyl alcohol on reaction with aldoxime and NaOCl in DCM gave exclusively (3-arylisoxazol-5-yl) methanol 1. The compound 1 was oxidized to an aldehyde 2 followed by reaction with aniline resulted in Schiff's base 3. The compounds 3 were further reacted with various aldehydes having α-hydrogen using molecular iodine as catalyst and which yielded 5-(3-alkylquinolin-2-yl)-3-aryl isoxazole derivatives 4. All the final compounds 4 were screened against four human cancer cell lines (A549, COLO 205, MDA-MB 231 and PC-3) and among these compounds 4n showed potent cytotoxicity against all the cell lines at IC50 values of <12 µM.

Synthesis of novel 2-alkyl triazole-3-alkyl substituted quinoline derivatives and their cytotoxic activity.

The propargyl alcohol on reaction with alkylazides under Sharpless conditions through click chemistry concept gave exclusively 1,4-disubstituted triazoles 2. The compounds 2 were oxidized to aldehydes 3 followed by reaction with aniline resulted Schiff's bases 4. The compounds 4 was further reacted with various aldehydes having α-hydrogen using molecular iodine as a catalyst and obtained 2-alkyl triazole-3-alkyl substituted quinoline derivatives 5. All the final compounds were screened against four human cancer cell lines (THP-1, Colo205, U937 & HeLa) and promising compounds have been identified.

Synthesis of novel alkyltriazole tagged pyrido[2,3-d]pyrimidine derivatives and their anticancer activity.

A series of novel alkyltriazole tagged pyrido[2,3-d]pyrimidine derivatives 5 and 6 was prepared starting from 2,3-active functional pyridine 1via cyclization, propargylation followed by reaction with alkyl or perfluoroalkyl azides under Sharpless conditions. All the compounds 5 and 6 were screened for anticancer activity against three cancer cell lines such as U(937), THP-1 and Colo205. The promising compounds 5b and 5e have been identified.