合成路线1

The synthesis of (2S,3S)-3-(2,4-difluorophenyl)-3-hydroxy-2-methyl-4-(1,2,4-triazol-1-yl)butyronitrile (XV), a key intermediate the synthesis of ER-30346 has been described: The tritylation of 3-hydroxy-2(S)-methylpropionic acid methyl ester (I) with trityl chloride in hot pyridine gives the trityl ether (II), which is hydrolyzed with LiOH in H2O/THF/methanol yielding the free acid (III). The esterification of (III) with 2-mercaptopyridine (IV) by means of dicyclohexylcarbodiimide (DCC) in dichloromethane gives the thioester (V), which is treated with 2,4-difluorophenylmagnesium bromide (VI) in THF yielding the propiophenone (VII), which by treatment with methyltriphenylphosphonium bromide/NaH in THF is converted into the methylene derivative (VIII). The oxidation of (VIII) with OsO4 and N-methylmorpholine oxide in acetone affords, after column chromatography, the chiral diol (IX), which is monomesylated with mesyl chloride/triethylamine in dichlormethane giving the monoester (X). The reaction of (X) with 1,2,4-triazol (XI) and NaH in DMF yields (2R,3S)-2-(2,4-difluorophenyl)-3-methyl-1-(1,2,4-triazol-1-yl)-4-(triphenylmethoxy)-2-butanol (XII), which is detritylated with p-toluenesulfonic acid in methanol affording the diol (XIII). The oxidation of (XIII) with oxalyl chloride/DMSO in dichloromethane gives the aldehyde (XIV), which is finally treated with hydroxylamine-O-sulfonic acid in water yielding the desired bytyronitrile intermediate (XV) already referenced.