Sulfuric Acid → 4-[1-(acetoxymethyl)propyl]-N-(1,3-dithiolan-2-ylidene)aniline dihydrogen sulfate

Participants

Reaction Steps

To a mixture of 3 g of 2-[4-(1,3-dithiolan-2-ylideneamino)phenyl]butanol and 1.25 g of triethylamine in 50 ml of dried methylene chloride was added dropwise a solution of 0.88 g of acetyl chloride in 25 ml of methylene chloride. The resulting solution was stirred at room temperature for 3 hours. It was then washed once with 0.1 N hydrochloric acid, twice with water, and once with saturated aqueous sodium chloride solution and dried over magnesium sulfate. The solid was removed to leave a crude orange oil which was purified by flash chromatography using 15 cm of silica gel and ethyl acetate/hexane as eluant. This gave a colorless oil which was 4-[1-(acetoxymethyl)propyl]-N-(1,3-dithiolan-2-ylidene)aniline. This oil was dissolved in 150 ml of diethyl ether and there was added dropwise a solution of 1.2 g of sulfuric acid in 75 ml of diethyl ether. When the addition was complete, the mixture was placed in a freezer. The precipitate which formed was separated by filtration and recrystallized from acetone/diethyl ether to give 4-[1-(acetoxymethyl)propyl]-N-(1,3-dithiolan-2-ylidene)aniline dihydrogen sulfate as white platelets melting at about 128.5°-131° C. The free base of this compound has the following structural formula ##STR4##

Provenance & Evidence