合成路线1

The target compound was obtained by several related ways. Indolylethanol (III) was either prepared by alkylation of indole (I) with methyl bromoacetate, followed by reduction of the resulting indolylacetate (II) with LiAlH4 or by alkylation of (I) with 2-bromoethanol. Alkylation of (III) with 4-fluorobenzaldehyde (IV) in the presence of NaH or condensation with 4-hydroxybenzaldehyde (V) under Mitsunobu conditions provided ether (VII). Alternatively, (VII) was prepared by alkylation of indole (I) with 4-(bromoethoxy)benzaldehyde (VI). Then, Knoevenagel condensation of aldehyde (VII) with 2,4-thiazolidinedione (VIII) in the presence of piperidinium benzoate in refluxing toluene with azeotropic removal of water yielded benzylidene compound (IX). Reduction of the olefinic double bond by either hydrogenation in the presence of an excess of Pd/C or by chemical reduction with Mg in MeOH provided the target benzyl compound. Alternatively, indolylethanol (III) was condensed with hydroxybenzyl compound (X) in the presence of tributyl phosphine and 1,1'-(azodicarbonyl)dipiperidine (ADDP) in benzene to give (XI), which was finally deprotected by hydrogenation in the presence of an excess of Pd/C in dioxan.