反应详情

In the same way as in Example 1, 150 mg (0.5 mmol) of (2R*,4R*)-4-(3-fluoro-2-methoxyphenyl)-2-hydroxy-2-(trifluoromethyl)pentanal, 100 mg (0.51 mmol) of 5-amino-7,8-difluoro-2-methylquinazoline and 0.2 ml of titanium tetraethoxide are reacted to give (2R*,4R*)-1-[(7,8-difluoro-2-methylquinazolin-5-yl)imino]-4-(3-fluoro-2-methoxyphenyl)-2-(trifluoromethyl)pentan-2-ol. 240 mg of resultant crude imine are cyclized in the same way as in Example 1 at −30° C. using 4 ml (4 mmol) of 1 M boron tribromide solution to give the desired product. Column chromatography on silica gel (hexane/ethyl acetate 50%) yields 30 mg of product.