合成路线1

The reaction of ethyl 2-sulfanylacetate (I) with 2-bromoacetonitrile (II) by means of NaOEt in ethanol gives ethyl 2-(cyanomethylsulfanyl)acetate (III), which is cyclized with diethyl oxalate (IV) by means of NaOEt in ethanol yielding 5-cyano-3,4-dihydroxythiophene-2-carboxylic acid ethyl ester (V). The protection of the hydroxyl groups of (V) with 2-methoxyethoxymethyl chloride (Mem-Cl) and DIEA in dichloromethane affords the protected thiophene (VI), which is reduced with (t-BuO)2AlH in THF providing the carbinol (VII). The oxidation of (VII) with MnO2 in dichloromethane yields the carbaldehyde (VIII), which is condensed with malonodinitrile (IX) by means of piperidine in dioxane giving the alkylidenemalonodinitrile (X). The epoxidation of (X) with tert-butyl hydroperoxide and TEA in dioxane yields the epoxide (XI), which is treated with HCl in THF to afford 2-chloro-2-[5-cyano-3,4-bis(2-methoxyethoxymethoxy) thiophen-2-yl]acetic acid (XII). The esterification of (XII) with diphenyldiazomethane affords the corresponding diphenylmethyl ester (XIII), which is condensed with N-hydroxyphthalimide (XIV) and NaHCO3 in dichloromethane providing the adduct (XV). The cleavage of the phthalimido group of (XV) with hydrazine in methanol gives 2-(aminooxy)-2-[5-cyano-3,4-bis(2-methoxyethoxymethoxy)thiophen-2-yl]acetic acid diphenylmethyl ester (XVI), which is condensed with 2-oxo-2-[2-(tritylamino)thiazol-4-yl]acetic acid (XVII) yielding the corresponding alcoxyimino derivative (XVIII).