合成路线1

The reaction of 3,3-dimethylglutaric acid monomethyl ester (XI) with SOCl2 in dichloromethane gives the monoacyl chloride (XII), which is condensed with thiophene (III), by means of SnCl4 in dichloromethane yielding the 5-oxopentanoic ester (XIII). The reduction and simultaneous hydrolysis of (XIII) with hydrazine and KOH affords the pentanoic acid (XIV), which is reesterified with ethanol and sulfuric acid to the ester (XV). The condensation of (XV) with the previously described 2-phenylacetyl chloride (II) by means of SnCl4 in dichloromethane gives the ethanone derivative (XVI), which is reduced with hydrazine and KOH to the previously described pentanoic acid (VIII). Its condensation with piperazine (IX) to afford (X) and the final reduction to the target compound have already been described.