Sodium Hydroxide → 1,8-Dihydro-2-[[(5-methyl-2-pyridyl)methyl]thio]-m-dioxino(4,5-f)benzimidazole dihydrochloride

Beteiligte Stoffe

Reaktionsschritte

To 3.7 g of 1,8-dihydro-m-dioxino(4,5-f)benzimidazole-2-thiol, suspended in 60 ml of alcohol, were added dropwise while stirring 1.5 g of sodium hydroxide in 30 ml of water and, after 30 minutes, there were added 3.4 g of 5-methyl-2-chloromethylpyridine hydrochloride. The mixture was left to boil at reflux overnight, then evaporated and the residue was taken up in methylene chloride. This mixture was washed first with 3 N sodium hydroxide, then neutral with water, dried over sodium sulfate and evaporated in vacuo. The crude product was dissolved while heating in a small amount of methanol and treated with 25 ml of 5 N hydrochloric acid in ethylacetate. There was obtained 1,8-dihydro-2-[[(5-methyl-2-pyridyl)methyl]thio]-m-dioxino(4,5-f)benzimidazole dihydrochloride of melting point 153°-155° C.

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