合成路线1

The condensation between 4-fluoronitrobenzene (I) and tetrazole (II) provided a mixture of regioisomeric (4-nitrophenyl)tetrazoles (III) and (IV). Reduction of this mixture employing hydrazine and FeCl3 gave the corresponding mixture of amino derivatives from which the required isomer (V) was isolated by column chromatography. Alternatively, 4-nitroaniline (VI) was converted into the desired (4-nitrophenyl)tetrazole regioisomer (III) by reaction with sodium azide and trimethyl orthoformate in HOAc. Subsequent reduction of the nitro group of (III) employing hydrazine and FeCl3 gave aniline (V). This compound was also obtained by another alternative procedure consisting in protection of 4-nitroaniline (VI) as the N,N-dibenzyl amine (VII), followed by reduction of the nitro group and cyclization with NaN3 and trimethyl orthoformate to afford tetrazole (VIII). Further hydrogenolysis of the benzyl protecting groups of (VIII) yielded 1-(4-aminophenyl)tetrazole (V). Aniline (V) was then converted to the intermediate phenyl carbamate (IX) by treatment with phenyl chloroformate in pyridine. Optionally, the intermediate phenyl carbamate (IX) was converted into the aryl imidazolone (XII) by condensation with 2,2-diethoxyethylamine (X) and then acid-catalyzed cyclization of the resulting N-(2,2-diethoxyethyl)urea (XI) to give (XII).