The reaction of N-cyclopentyl-indole-3-carboxaldehydes with substituted acetophenones in ethanol and KOH as a base gives N-cyclopentylindolylchalcones [3a-3l]. Which on treatment with urea in presence of base resulted in the cyclization of α, β-unsaturated ketone into the substituted pyrimidines [4a-4l] with goodyield after purification. The synthesized compounds were characterised by 1H-NMR, IR and Mass and screened for their Anti-microbial activity.