New mannich bases of 1(-(1-((1-(morpholinomethyl/piperidin-1-ylmethyl/(4-methyl piperazine-1-yl)methyl))-6- nitro-1H-benzo[d]imidazole-2-yl)methyl)-6-oxido-4,8-dihydro-1H-[1,3,2] dioxaphosphepino [5,6-c] pyrazole-6-yl)- 3-(phenyl/p-tolyl/4-methoxy phenyl/4-chloro phenyl) ureas 9(a-j) were prepared by condensation reaction between1-((1-(piperidin-1-ylmethyl)/(1-morpholino methyl)/(4-methyl piperazin-1-ylmethyl)-6-nitro-1H-benzo [d] imidazol-2-yl) methyl)-1H-pyrazole-4, 5-diyl) dimethanol 7(a-c) and (phenyl carbamoyl) phosphoric acid dichlorides 8(a-g).The synthon 7(a-c) was obtained by deprotection of isopropilidine group of 6,6-dimethyl-1-((6- nitro-1-((1-(piperidin-1-ylmethyl)/ (1-morpholinomethyl)/ (4-methyl piperazin-1-ylmethyl)-1H-benzo[d]imidazol-2- yl)methyl)-4,8-dihydro-1H-[1,3]- dioxepIno [5,6-c] pyrazole 6(a-c).The synthon 6(a-c) was obtained by mannich reaction of 6, 6-dimethyl-1-((6-nitro-1H-benzo[d]imidazol-2-yl) methyl-4, 8-dihydro-1H-[1, 3] - dioxepino [5, 6-c] pyrazole (5) with different secondary amines having hetero atom in cyclic ring and HCHO in presence of DMF.The synthon 5 obtained by condensation reaction between 2-(6, 6-dimethyl-4, 8-dihydro-1H-[1, 3] dioxepino [5, 6-c] pyrazole-1-yl) acetic acid 3 and 4-nitro benzene 1,2-amine. Similar procedure was adapted to prepare N-(1-((1- morpholinomethyl)-1H-benzo[d]imidazol-2-yl)methyl)-6-oxido-4,8-dihydro-1H-[1,3,2]dioxaphosphepino[5,6- c]pyrazol-6-yl)morpholine piperadine/4-methylpiperazine carboxamides (9k-m).