The condensation of 5-chlorosalicyialdehyde (I) with 4-chloromethylpyridine (II) by means of K2CO3 / KI in hot DMF gives 5-chloro-2-[(4-pyridyl)methoxy]benzaldehyde (III), which is cyclized by heating at 300 C to afford 5-chloro-2-(4-pyridyl)benzofurane (IV). Quaternization of (IV) with methyl iodide in hot methanol yields 1-methyl-4-(5-chloro-2-benzofuranyl)pyridinium iodide (V), which is hydrogenated with NaBH4 in methanol giving 5-chloro-2-(1-methyl-1,2,3,6-tetrahydro-4-pyridyl)benzofurane (VI). Finally, this compound is hydrogenated further with H2 over PtO2 in methanol.

The condensation of 5-chlorosalicyialdehyde (I) with 4-chloromethylpyridine (II) by means of K2CO3 / KI in hot DMF gives 5-chloro-2-[(4-pyridyl)methoxy]benzaldehyde (III), which is cyclized by heating at 300 C to afford 5-chloro-2-(4-pyridyl)benzofurane (IV). Quaternization of (IV) with methyl iodide in hot methanol yields 1-methyl-4-(5-chloro-2-benzofuranyl)pyridinium iodide (V), which is hydrogenated with NaBH4 in methanol giving 5-chloro-2-(1-methyl-1,2,3,6-tetrahydro-4-pyridyl)benzofurane (VI). Finally, this compound is hydrogenated further with H2 over PtO2 in methanol.