The present invention relates to a process for the preparation of olopatadine and, more particularly, to an improved method of synthesizing olopatadine which comprises reacting a dibenzb,eoxepin-11-one derivative of formula and a suitable reagent under Witting condition, and to the intermediate 11–3–propylidene-6-11-dihydrodibenzb,e-oxepin-2-acet-amide p-toluensulfonate salt. A stator is held on a first holding plate and a second holding plate. A device isolation layer is formed on the second silicon nitride pattern, and a top surface of the device isolation layer is coplanar with top surfaces of the oxide pattern and the second silicon nitride pattern. The fine powder and whole leaves are added to hot water for a period of time to form a brewed tea.