Hydrochloric Acid → 5-Methoxy-[1,2,5]triazepane-1,2-dicarboxylic acid di-tert-butyl ester hydrochloride salt

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Reaction Steps

A solution of 5-methoxy-[1,2,5]triazepane-1,2-dicarboxylic acid di-tert-butyl ester in diethyl ether was treated with gaseous hydrogen chloride to generate a white precipitate. The solid was filtered, washed with diethyl ether and dried to afford 5-methoxy-[1,2,5]triazepane-1,2-dicarboxylic acid di-tert-butyl ester hydrochloride salt. To a suspension of 5-methoxy-[1,2,5]triazepane-1,2-dicarboxylic acid di-tert-butyl ester hydrochloride salt (2.5 g, 6.8 mmol) in ethyl acetate (10 ml) was added a solution of hydrogen chloride in 1,4-dioxane (4 M, 9 ml, 36.0 mmol) at room temperature dropwise. The reaction mixture was heated at 90° C. for one hour, the solvent evaporated, the residue washed with diethyl ether and dried in vacuo. Yield: 1.4 g of 5-methoxy-[1,2,5]triazepane hydrochloride salt (compound P4.2) as a yellowish solid, this material was used without further purification.

Provenance & Evidence