合成路线1

This compound can be obtained by two different ways: 1) The acetylation of 1-nitrosopiperazine (I) with acetyl chloride and pyridine in dioxane gives 1-acetyl-4-nitrosopiperazine (II), which is reduced with Zn and acetic acid/water to 1-acetyl-4-aminopiperazine (III). Finally, this compound is acylated with 4-fluorobenzoyl chloride (IV) by means of triethylamine in dichloromethane. 2) The nitrosation of piperazine (V) with NaNO2/HCl in water, followed by condensation with benzyloxycarbonyl chloride (VI) by means of NaOH yields 1-(benzyloxycarbonyl)-4-nitrosopiperazine (VII), which is reduced with Zn and acetic acid/water as before to the corresponding amino derivative (VIII). The acylation of (VIII) with 4-fluorobenzoyl chloride and triethylamine in dichloromethane affords N-[4-(benzyloxycarbonyl)piperazin-1-yl]-4-fluorobenzamide (IX), which is deprotected with HBr in acetic acid to yield N-(1-piperazinyl)-4-fluorobenzamide (X). Finally, this compound is acetylated with acetic anhydride/NaOH in water.