合成路线1

This compound can be obtained by three related ways: 1) The carboxylation of 3-ethoxy-4-pentyloxyiodobenzene (I) with CO2 and butyllithium in ether gives 3-ethoxy-4-pentyloxybenzoic acid (II), which is reduced with LiAlH4 in refluxing ether to yield the corresponding benzyl alcohol (III). The controlled oxidation of (III) with pyridinium chlorochromate in dichloromethane affords 3-ethoxy-4-pentyloxybenazldehyde (IV), which is treated wtih NaCN and acetic acid - water giving 2-(3-ethoxy-4-pentyloxyphenyl)-2-hydroxyacetonitrile (V). Finally, this compound is cyclized with thiourea (VI) and HCl in 2-methoxyethanol. 2) The alkylation of ethyl-vanilline (VII) with c and K2CO3 in hot DMF gives aldehyde (IV), which by reaction with NaCH in methanol - HCl yields the cyanohydrine (V). The reaction of (V) with SOCl2 in refluxing CHCl3 affords 2-chloro-2-(3-ethoxy-5-pentyloxyphenyl)acetonitrile (VIII), which is finally cyclized with thiourea (VI) in ethylene glycol monomethyl ether - HCl at 110 C in refluxing ethanol - HCl. 3) The cyclization of 2-(3-ethoxy-4-pentyloxyphenyl)-2-hydroxyacetic acid (IX) with thiourea (VI) under acidic conditions gives 5-(3-ethoxy-4-pentyloxyphenyl)-2-iminothiazolidin-4-one (X), which is then hydrolyzed to the desired product.