A series of novel pyrazole derivatives bearing pyran, pyridine, pyrazole, imidazol, 1,3 oxazole and 1,3,4-thiadiazole 4a,b, 5a,b, 6, 8, 9 and 14a-g have been synthesized. 2-Amino-4-(3-methyl-1-phenyl-1H -pyrazol-4-yl)-4H-benzo[g]chromene-3-carbonitrile derivative 15 was synthesized under microwave irradiation. Also compound 15 was used for the synthesis of benzo[g]chromene derivatives 16 & 17 and benzo[g] chromene[2,3-d] pyrimidine derivative 19. The structure of the newly synthesized compounds was elucidated on the basis of analytical and spectral analyses. All the synthesized compounds screened for the anticancer activity against three tumor cell lines using doxorubicin as standard. Compounds 5b (IC50 =0.36, 0.28, 0.32 µmol L-1) and 14b (IC50 =0.38, 0.32, 0.22 µmol L-1) has excellent cytotoxic agents against the three tumor cell lines, which is more potent than the activity of doxorubicin.