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 3N 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 5N 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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