Demiditraz IMpurity synthesis

Yield:-

Reaction Conditions:

with triethylamine in acetonitrile; for 18 h;Product distribution / selectivity;Heating / reflux;

Steps:

36

A solution of 2,3-dimethylbenzoic acid (100 g, 666 mmol) in thionyl chloride (350 ml) was heated at 80° C. for 1 h, before cooling to room temperature and concentrating in vacuo. To the residue was added toluene (100 ml) and the solution was again concentrated in vacuo. The intermediate acid chloride was added to a mixture of 1-benzylimidazole (100 g, 632 mmol) and triethylamine (100 ml) in acetonitrile (1 l) and the reaction mixture was heated at reflux for 18 h. The reaction mixture was concentrated in vacuo and to the residue was added diethyl ether (500 ml) and ethyl acetate (50 ml). This solution was washed with water (500 ml) and saturated aqueous sodium hydrogen carbonate solution (500 ml), filtered through silica gel (100 g) and concentrated in vacuo to give the title compound (182 g).Experimental MH⁺ 291.4; expected 291.1

References:

US2007/167506,2007,A1 Location in patent:Page/Page column 106