5-amino-8-fluoroquinolin-2(1H)-one → 8-fluoro-5-{[(2R*,4R*)-4-(3-fluoro-2-methoxyphenyl)-2-hydroxy-2-(trifluoromethyl)pentylidene]amino}quinolin-2(1H)-one

Participants

Reaction Steps

In the same way as in Example 1, 300 mg (1.01 mmol) of (2R*,4R*)-4-(3-fluoro-2-methoxyphenyl)-2-hydroxy-2-(trifluoromethyl)pentanal, 180 mg (1.01 mmol) of 5-amino-8-fluoroquinolone and 0.48 ml of titanium tetraisopropoxide in 9 ml of xylene are reacted to give 8-fluoro-5-{[(2R*,4R*)-4-(3-fluoro-2-methoxyphenyl)-2-hydroxy-2-(trifluoromethyl)pentylidene]amino}quinolin-2(1H)-one. 80 mg of imine purified by column chromatography (silica gel, hexane; CH2Cl2/i-PrOH 0-5%) are cyclized, in the same way as in Example 1, at −40° C. using 1.7 ml (1.5 mmol) of 1 M boron tribromide solution to give the desired product and the ether-cleaved Example 8.

Provenance & Evidence