合成路线1

The condensation of 2,4,5-trifluoro-3-methoxybenzoyl chloride (I) with 14C-labeled diethyl malonate (II) by means of MgCl2 and TEA gives the benzoylmalonate (III), which is monodecarboxylated with TsOH in refluxing water, yielding the benzoylacetate (IV). The reaction of (IV) with triethyl orthoformate and Ac2O at 140 C affords the benzoylacrylate (V), which is treated with cyclopropylamine (VI) in cyclohexane to provide ethyl 3-(cyclopropylamino)-2-(2,4,5-trifluoro-3-methoxybenzoyl)acrylate (VII). The cyclization of (VII) by means of K2CO3 in hot N-methylpyrrolidone gives the quinolone carboxylate (VIII), which is hydrolyzed with NaOH in hot methanol, affording the carboxylic acid (IX). Finally, this compound is condensed with (S,S)-2,8-diazabicyclo[4.3.0]octane (X) by means of 1,4-diazabicyclo[2.2.2]octane (DABCO) in refluxing acetonitrile.