Amino thiophene carbonitrile 1 reacted with chloropyrazole carbaldehyde 2a,b to afford Schiff bases 3a,b in good yield via condensation reaction. Compounds 3a,b reacted with different primary and secondary amines to afford pyrazolo derivatives 4-10. Also, one-pot Kabachnic-Fields reaction invloved the synthesis of α-aminophosphonates by condensation of pyrazole-5-carbaldehyde derivatives, N-heterocyclic amines and trialkylphosphites in moderate yields. α-Aminophosphonates were also produced in high yields (75%) by reacting Schiff bases directly with dialkylphosphites. In addition, hexaalkyl triamidophosphites were applied to the Schiff bases in THF to afford the amino derivatives in high yields. Molecular modelling investigations were studied to explore the possible binding interactions which revealed that compounds 8, 7, and 3b were the most promising candidates comparing with Doxorubicin. Antitumor activity of new compounds was tested on three cell lines of liver (HepG2), breast (MCF7) carcinoma cell lines and HCT-116 cancer cells together with human healthy cell line (BJ-1) using the MTT assay.