Methanol → Ethyl [5-(1,2-dithiolan-3-yl)pentyl]carbamate

Participants

Reaction Steps

2 ml of methanol and 2 ml of butylamine were added to a solution of 1.6 mmol of 2-[5-(1,2-dithiolan-3-yl)pentyl]isoindole-1,3-dione in 3 ml of toluene. The resulting mixture was stirred at room temperature for 7 hours. At the end of this time, the reaction mixture was allowed to stand overnight at room temperature. The solvent was then removed from the reaction mixture by distillation under reduced pressure. Water was added to the resulting residue, after which it was extracted with ethyl acetate. The extract was washed with a saturated aqueous solution of sodium chloride and then dried over anhydrous sodium sulfate. Ethyl acetate was removed from the extract by distillation under reduced pressure. 2 ml of anhydrous tetrahydrofuran were added to the residue, and then 0.33 ml of triethylamine and 0.23 ml of ethyl chloroformate were added dropwise, whilst ice-cooling. The resulting mixture was stirred at room temperature for 2 hours. The solvent was then removed from the reaction mixture by distillation under reduced pressure. Water was added to the residue, after which it was extracted with ethyl acetate. The extract was washed with a saturated aqueous solution of sodium chloride and then dried over anhydrous sodium sulfate. Ethyl acetate was removed from the extract by distillation under reduced pressure, and the residue was subjected to silica gel column chromatography, using 1:3 and 1:2 by volume mixtures of ethyl acetate and hexane as eluent, followed by reverse phase preparative silica gel column chromatography, using a 1:1 by volume mixture of acetonitrile and water as eluent. Acetonitrile was removed from the eluate so obtained by distillation under reduced pressure, and the residue was extracted with ethyl acetate. The extract was washed with a saturated aqueous solution of sodium chloride and then dried over anhydrous sodium sulfate. Ethyl acetate was removed from the extract by distillation under reduced pressure. The residue was dissolved in dioxane, after which it was lyophilised, to give 75 mg of the title compound as a red oil having an Rf value of 0.46 (silica gel thin layer chromatography; using a 1:2 by volume mixture of ethyl acetate and hexane as the developing solvent).

Provenance & Evidence