5-amino-1(2H)-phthalazinone → 5-{[(2R*,4R*)-4-(3,4-difluoro-2-methoxyphenyl)-2-hydroxy-2-(trifluoromethyl)hexylidene]amino}phthalazin-1-one

Participants

Reaction Steps

In the same way as in Example 29, 372 mg (1.14 mmol) of (2R*,4R*)-4-(3,4-difluoro-2-methoxyphenyl)-2-hydroxy-2-(trifluoromethyl)hexanal, 200 mg (1.14 mmol) of 5-aminophthalazin-1-one and 0.36 ml of titanium tetra-tert-butoxide are reacted to give 5-{[(2R*,4R*)-4-(3,4-difluoro-2-methoxyphenyl)-2-hydroxy-2-(trifluoromethyl)hexylidene]amino}phthalazin-1-one. 560 mg of crude imine are cyclized in the same way as in Example 29 at −30° C. with 11.8 ml (11.8 mmol) of 1 M boron tribromide solution to give the desired product. Preparative thin-layer chromatography on silica gel (hexane/2-propanol 17%) yields 249 mg of the desired product

Provenance & Evidence