The histamine H3 receptor subtype negatively modulates the release of various neurotransmitters such as histamine, glutamate, norepinephrine, acetylcholine and many others mainly in the CNS and H3 antagonists have been developed to treat central diseases characterized by neurotransmission disturbance such as schizophrenia, memory/learning and sleep disorders. The imidazole-free derivatives possessed moderate to pronounced antagonistic potency at guinea-pig ileal H3 receptor consistent with binding affinity at rat brain H3 receptors and showed a favourable receptor selectivity profile .Computer aided drug designing of 1 – alkyl -4 acyl piperazine derivative was performed by Argus Lab software .The minimum potential energy is calculated by grometery convergence function by Argus Lab software .The most feasible postion for the drug to interact with the recptor was found to be 38.2539624 kcal /mol
