合成路线1

The demethylation of 6-methoxy-3,4-dihydro-2H-1-benzopyran-4-one (I) with 48% HBr in refluxing acetic acid gives the corresponding hydroxy compound (II), which is protected with benzyl bromide and K2CO3 in acetone yielding the benzyl ether (III). The condensation of (III) with 3-formyl-4-methoxybenzoic acid methyl ester (IV) by means of pyrrolidine in methanol affords the benzylidene derivative (V), which is reduced to the corresponding benzyl analogue (VI) with H2 over Pd/C in ethyl acetate. The reduction of the ketone group of (VI) with NaBH4 in MeOH/THF in the presence of CeCl3 gives the expected cis alcohol as a racemic mixture, which is submitted to optical resolution by esterification with Boc-D-tryptophan, chromatographic separation of the diastereomeric mixture, and basic hydrolysis of the ester groups yielding the (3S,4R)-alcohol (VII). The Curtius rearrangement of (VII) by reaction with diphenylphosphoryl azide (DPPA), benzyl alcohol and triethylamine affords carbamate (VIII), which is treated with H2 over Pd(OH)2 in dioxane to give the amine (IX). The condensation of (IX) with 7-chloro-2-(chloromethyl)quinoline (X) by means of NaH in DMF yields the corresponding ether (XI), which is finally treated with trifluoromethanesulfonic anhydride and triethylamine in dichloromethane to afford the target sulfonamide.