4-(4-Nitro-3-benzyloxyphenoxy)-2-(4-benzyloxycarbonylphenoxy)-3,5,6-trifluoropyridine → 4-(4-Amino-3-hydroxyphenoxy)-2-(4-carboxyphenoxy)-3,5,6-trifluoropyridine

Participants

Reaction Steps

40 g of the 4-(4-nitro-3-benzyloxyphenoxy)-2-(4-benzyloxycarbonylphenoxy)-3,5,6-trifluoropyridine prepared as described in Example 7 (0.066 mol) are dissolved in 600 ml of a mixture of tetrahydrofuran and ethyl acetate (volume ratio 1:1), and 4 g of Pd/C (palladium/carbon) are added to the solution. The mixture is then hydrogenated using hydrogen at a pressure of 1 bar at room temperature in an autoclave with vigorous stirring; the reaction is terminated after 3 days. The orange solution is evaporated to half in a rotary evaporator and left to stand overnight at room temperature, during which the reaction product precipitates out in crystalline form. The reaction product is then dried for 48 hours under nitrogen at 40° C./10 mbar in a vacuum drying cabinet (yield: 91%).

Provenance & Evidence