合成路线1

Michael addition of methyl vinyl ketone (II) to phthalimide (I) in the presence of NaOEt afforded phthalimido ketone (III). Bromination of (III) in MeOH, followed by acid hydrolysis of the resulting dimethyl ketal provided bromo ketone (IV). Cyclization of bromo ketone (IV) with thiourea (V) yielded the amino thiazole (VI) and further deprotection of the phthalimido group of (VI) in refluxing HBr furnished diamine (VII). 3,5-Diiodo-4-methoxyphenylacetic acid (VIII) was converted to the corresponding acid chloride (IX) using oxalyl chloride, and subsequently coupled with amine (VII) under Schotten-Baumann conditions to give amide (X). Cyclization of (X) to the thiazolopyridine (XI) was effected by the Bischler-Napieralski procedure employing POCl3 in acetonitrile. The imine double bond of (XI) was then reduced by means of NaBH4, and the resulting compound was finally converted to the dihydrochloride salt.