5-Amino-2-methylphthalazin-1-one → 5-{[4-(3-Fluoro-2-methoxyphenyl)-2-hydroxy-2-(trifluoromethyl)hexylidene]amino}-2-methylphthalazin-1-one

Participants

Reaction Steps

In the same way as in Example 29, 265 mg (0.86 mmol) of 4-(3-fluoro-2-methoxyphenyl)-2-hydroxy-2-(trifluoromethyl)hexanal, 150 mg (0.86 mmol) of 5-amino-2-methylphthalazin-1-one and 0.42 ml of titanium tetraethoxide are reacted to give 5-{[4-(3-fluoro-2-methoxyphenyl)-2-hydroxy-2-(trifluoromethyl)hexylidene]amino}-2-methylphthalazin-1-one. 410 mg of crude imine are cyclized in the same way as in Example 29 at −20° C. with 3.5 ml (3.5 mmol) of 1 M boron tribromide solution to give the desired product. Column chromatography on silica gel (hexane/ethyl acetate 50%) and subsequent preparative thin-layer chromatography on silica gel with dichloromethane/methanol 9:1 yield 10 mg of product and 8.6 mg of the 8α compound (Example 45).

Provenance & Evidence