合成路线1

ABT-431 can be obtained by two related ways: 1) The reduction of 6,7-dimethoxy-1-tetralone (I) with NaBH4 in ethanol followed by dehydration with p-toluenesulfonic acid in refluxing toluene gives 6,7-dimethoxy-1,2-dihydronaphthalene (II), which is nitrated with tetranitromethane and pyridine in acetone yielding 6,7-dimethoxy-3-nitro-1,2-dihydronaphthalene (III). The condensation of (III) with N-tert-butyl-5-propylthiophene-2-carboxamide (IV) by means of butyllithium in THF affords the trans racemic (V), which is reduced with Zn/HCl to the corresponding amine (VI). The reaction of (VI) with 10% H2SO4 in refluxing methanol gives a mixture of the decarboxylated compound (VII) and the cyclization compound (VIII). The enantiomeric separation of (VIII) by chiral chromatography in a Chiracel(TM) OD column affords the (5aR,11bS)-enantiomer, which is demethylated with BBr3 in dichloromethane to the chiral diol (IX), and finally acetylated with acetyl chloride in trifluoroacetic acid and treated with ethereal HCl. 2) The condensation of (III) with 5-allyl-N-tert-butylthiophene-2-carboxamide (X) by means of butyllithium in THF affords the trans racemic (XI), which by successive treatments with Zn/HCl, hydrogenation with H2 over Pd/C, p-toluenesulfonic acid in refluxing toluene and finally with BH3 in THF, is converted into the previously reported tetracyclic racemic compound (VIII). N-tert-Butyl-5-propylthiophene-2-carboxamide (IV) has been obtained by condensation of 2-propylthiophene (XII) with tert-butyl isocyanate (XIII) by means of butyllithium in THF.