Hydrochloric Acid → Ethyl (4-iodo-2-methyl-5,6,7,8-tetrahydro[1]benzothieno[2,3-b]pyridin-3-yl)carboxylate

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Reaction Conditions

Reaction Steps

To a solution of ethyl (4-chloro-2-methyl-5,6,7,8-tetrahydro[1]benzothieno[2,3-b]pyridin-3-yl)carboxylate (10 g; 32.3 mmol) in tetrahydrofurane (100 ml) at room temperature was slowly added a 4N solution of hydrochloric acid in dioxane (56.5 mL; 226 mmol). The mixture was stirred at 60° C. for 1 h and then concentrated under reduced pressure. The residue was dissolved in acetonitrile (75 mL), sodium iodide (38.7 g; 258 mmol) was added and the mixture was heated at reflux for 48 h. The volatiles were removed under reduced pressure, the residue dissolved in ethyl acetate and was successively washed with water, a solution of sodium thiosulphate, water and brine. The organics were dried over magnesium sulphate, filtered and concentrated under reduced pressure to afford 10.83 g (71%) of the title compound as a yellow solid.

Provenance & Evidence