反应详情

In the same way as in Example 1, 170 mg (0.58 mmol) of (2R*,4S*)-4-(3-fluoro-2-methoxyphenyl)-2-hydroxy-2-(trifluoromethyl)pentanal, 124 mg (0.60 mmol) of 5-amino-7,8-difluoro-2-methylquinazoline and 0.31 ml of titanium tetraethoxide are reacted to give (2R*,4S*)-1-[(7,8-difluoro-2-methylquinazolin-5-yl)imino]-4-(3-fluoro-2-methoxyphenyl)-2-(trifluoromethyl)pentan-2-ol. 85 mg of imine purified by column chromatography (silica gel, hexane/ethyl acetate 0-30%) are cyclized in the same way as in Example 1 at −20° C. using 0.72 ml (0.72 mmol) of 1 M boron tribromide solution to give the desired product. Preparative thin-layer chromatography on silica gel (hexane/ethyl acetate 50%) yields 15 mg of product.