5-Amino-2-methylphthalazin-1-one → 5-{[(2R*,4R*)-4-(3-fluoro-2-methoxyphenyl)-2-hydroxy-2-(trifluoromethyl)pentyliden]amino}-2-methylphthalazin-1-one

Participants

Reaction Steps

In the same way as in Example 1, 295 mg (1.0 mmol) of (2R*,4R*)-4-(3-fluoro-2-methoxyphenyl)-2-hydroxy-2-(trifluoromethyl)pentanal, 217 mg (1.0 mmol) of 5-amino-2-methylphthalazin-1-one and 0.53 ml of titanium tetraethoxide are reacted to give 5-{[(2R*,4R*)-4-(3-fluoro-2-methoxyphenyl)-2-hydroxy-2-(trifluoromethyl)pentyliden]amino}-2-methylphthalazin-1-one. 590 mg of resultant crude imine are cyclized, in the same way as in Example 1, at −30° C. using 10 ml (10 mmol) of 1 M boron tribromide solution to give the desired product. Column chromatography on silica gel (hexane/ethyl acetate 0-60%) yields 204 mg of product.

Provenance & Evidence