Easy synthetic approach to p-aminophenoxy derivatives bearing phosphonic or carboxylic ethyl ester groups

Condensation of the ethyl esters of phenyl carboxylic acids or phenyl-phosp honic acids with halonitrobenzenes in anhydrous acetonitrile in presence of potassium carbonate produces 4'-nitrophenoxy-benzoic or benzo-phosphonic a cid ethyl esters in good yields. This procedure, which represents a new app roach for the nucleophilic condensation, is particularly useful for substra tes bearing ancillary reactive groups for which the usual procedure describ ed in literature leads to decomposition products. Reduction of the parent n itro derivatives by hydrazine in the presence of palladium catalyst yields the corresponding amines in very high yield.