合成路线1

The intermediate 4-[4-(4-aminophenyl)piperazin-1-yl]phenol (VIII) has been obtained by several related ways: 1.- The condensation of 4-bromonitrobenzene (I) with piperazine (II) gives 1-(4-nitrophenyl)piperazine (III), which is condensed with 4-bromoanisole (IV) by means of Pdo to yield 1-(4-methoxyphenyl)-4-(4-nitrophenyl)piperazine (V). Alternatively, (V) can also be obtained by condensation of (III) with 4-methoxyphenylboronic acid (VI) by means of Cu(OAc)2 in DMSO. The demethylation of (V) with HBr yields 4-[4-(4-nitrophenyl)piperazin-1-yl]phenol (VII), which is finally reduced with H2 over Pd/C to afford the target 4-[4-(4-aminophenyl)piperazin-1-yl]phenol (VIII) intermediate (see Synthline, scheme no. 22656202a, intermediate (XIV)). 2.- The condensation of piperazine (II) with 4-bromoanisole (IV) by means of Pdo gives 1-(4-methoxyphenyl)piperazine (IX), which is condensed with 4-bromonitrobenzene (I) by means of K2CO3 and tetrabutylammonium iodide (TBAI) in hot DMSO to yield intermediate 1-(4-methoxyphenyl)-4-(4-nitrophenyl)piperazine (V), already reported. 3.- The condensation of piperazine (II) with 4-(benzyloxy)phenyl bromide (X) by means of Pdo gives 1-(4-benzyloxyphenyl)piperazine (XI), which is condensed with 4-bromonitrobenzene (I) by means of K2CO3 and TBAI in hot DMSO to yield 1-(4-benzyloxyphenyl)-4-(4-nitrophenyl)piperazine (XII). The nitro group of (XII) is reduced by means of H2 (50 psi) over Pd/C in wet THF at 50? C to afford 4-[4-(4-benzyloxyphenyl)piperazin-1-yl]aniline (XIII), which is finally debenzylated with H2 (80 psi) over Pd/C in wet THF at 70? C or other drastic conditions to afford the target 4-[4-(4-aminophenyl)piperazin-1-yl]phenol (VIII) intermediate (see Synthline, scheme no. 22656202a, intermediate (XIV)). Alternatively, 1-(4-benzyloxyphenyl)-4-(4-nitrophenyl)piperazine (XII) can also be reduced directly to the target intermediate (VIII) with H2 over Pd/C under a variety of drastic conditions.