113806-05-6

Patanol,Alcon,UK

Anti-allergic.

Olopatadine is a dual acting histamine H1-receptor antagonist and mast cell stabilizer. Antiallergic; antihistaminic.

ChEBI: 2-[11-[3-(dimethylamino)propylidene]-6H-benzo[c][1]benzoxepin-2-yl]acetic acid is a heterotricyclic compound.

402.4 g of phthalide and 200 g of sodium chloride and equal molecular quantity of p-hydroxyphenyl acetic acid are mixed with one another and stirred at 150°C for 6 hours. After completion of the reaction, the mixture is cooled until the temperature is brought back to room temperature, 4 L of aqueous 10% acetic acid solution is added thereto and the mixture is allowed to stand at room temperature overnight. After stirring the mixture at room temperature for 3 hours, deposited crystals are separated by filtration, and 6 L of water is added thereto. After stirring the mixture at room temperature for 30 minutes, the deposited crystals are separated by filtration. After the addition of 3 L of toluene to the crystals, the mixture is stirred at room temperature for one hour. The crystals are separated by filtration and dried over heating under reduced pressure to yield of 2-(4-acetoxyphenoxy)benzoic acid.
266.0 g of trifluoroacetic anhydride is added to the equal molecular quantity of 2-(4-acetoxyphenoxy)benzoic acid suspended in 5.0 L of methylene chloride and thereto. After stirring the mixture at room temperature for one hour, 19.4 g of boron trifluoride-ethylether complex is added thereto and the mixture is stirred at room temperature for two hours. The reaction solution is poured into ice water. After an organic solvent layer is separated from the mixture, the organic layer is washed with diluted aqueous sodium hydroxide solution and water, dried over anhydrous magnesium sulfate and concentrated under reduced pressure to obtain 335.3 g of methyl 11-oxodibenz[b,e]oxepin-2- carboxylate as a white crystal melting point 130°-132°C Methyl 11-methylene-6,11-dihydrodibenz-[b,e]oxepin-2-acetate.
In 100 ml of tetrahydrofuran is suspended 25 g of methyltriphenylphosphonium bromide and 40 ml of 1.6 N n-butyl lithium hexane solution is dropwise added thereto under a nitrogen atmosphere and ice-cooling. After stirring the mixture under ice-cooling for 30 minutes, a solution obtained by dissolving equal molar quantity of 11-oxo-6,11- dihydrodibenz[b,e]oxepin-2-acetic acid in 250 ml of tetrahydrofuran is dropwise added thereto and the mixture is stirred at room temperature for two hours. The solvent is distilled away under reduced pressure and the residue is purified by column chromatography on silica gel (eluent: hexane:ethyl acetate = 3:1) to obtain the desired product as a colorless oily matter.

Patanol (Alcon).

Antiallergic