| abstract |
The invention comprises a process for preparing quetiapine and/or its salts, including, quetiapine fumarate. The process generally comprises reacting dibenzothiazepinone (dibenzo[bf][l,4]thiazepin-l l(10H)-one) with phosphorous oxychloride in the presence of triethylamine in an aromatic organic solvent such as toluene or, preferably, xylene at reflux temperature to obtain an aromatic hydrocarbon solution of 11-chloro-dibenzo [bf] [1,4] thiazepine. Thereafter, the l l-chloro-dibenzo[bf][1,4] thiazepine is reacted with 2-(2-piperazin-l-ylethoxy)-ethanol to yield, following several processing steps, quetiapine.. Compound I can then be further reacted with fumaric acid at elevated temperature to yield quetiapine fumarate. The resulting quetiapine fumarate obtained is suitable for use in pharmaceutical preparations. |