Pyrazole linked benzimidazole conjugates and a method for synthesis of one or more compounds having a pyrazole linked benzimidazole conjugate, particularly pyrazole linked benzimidazole conjugates that are useful as potential antitumor agents against human cancer cell lines, such as leukemia, non-small cell lung cancer, colon cancer, CNS cancer, melanoma, ovarian cancer, renal cancer, prostate cancer and breast cancer. The process comprises the step of oxidative cyclization of o-phenylenediamines and 3-phenyl-1H-pyrazole-5-carbaldehydes with sodium metabisulphite in ethanol/methanol solvent system at a desired temperature for a period of time to obtain the pyrazole linked benzimidazole conjugate.