FT Calculations on Quetiapine Hemifumarate as a pharmaceutical compound for the treatment of schizophrenia

Quetiapine, is described 2-(2-(4-dibenzo(b,f)(1,4)thiazepine-11-yl-1-piperazinyl)ethoxy)ethanol wit molecular formula C21H25N3O2S and molecular weight 383.51 (Fig. 1). Quetiapine is used for the treatment of schizophrenia and recently has Food and Drug Administration (FDA) approval for treatmen of manic depression [1,2]. It is also to treat other disorders, such as post-traumatic stress disorde r alcoholism, obsessive compulsive disorder, anxiety disorders, and hallucinations in Parkinson s diseas patients using ropinirole and as a sedative for those with sleep disorders. Quetiapine is the mos commonly prescribed antipsychotic drug in America and has been used by more than 19 million patient worldwide in 1997. The mechanism of action of Quetiapine, as with other drugs having efficacy in the treatment of schizophrenia and acute manic episodes associated with bipolar disorder, is unknown. I this work, the optimization calculations were carried out on Quetiapine Hemifumarat and its ground stat conformations were compared with its obtained X-Ray data. These calculations were carried out by using B3LYP/6-31G(d) level of theory. The DFT calculations clarified a boat structure for dibenzothiaazepine part of the molecule which piperazine section was occurred in a chair conformation. The results will be presented and discussed.