Sulfuric Acid → HCID 86743820, compound

Participants

Reaction Steps

A mechanically stirred solution of 20.0 g of 4-isopropyl-4-methyl-2-p-tolyl-2-imidazolin-5-thione in 200 mL of dry tetrahydrofuran is treated dropwise with 160 mL of a 1.2M solution of sec-butyl lithium (0.191 mol) in cyclohexane over a 40 minute period at -72° to -65° C. After stirring the resulting solution at -40° to -35° for one and one-half hours, a solution of 21.4 g (0.090 mol) of hexachloroethane in 125 mL of dry tetrahydrofuran is added dropwise. Addition temperature is allowed to reach -20° C. After warming to room temperature over a 16 hour period, the reaction is treated with 200 mL of ice water plus 200 mL of a saturated sodium chloride solution. The mixture is carefully acidified to pH 3 with concentrated sulfuric acid. The phases are separated and the aqueous phase is extracted with 200 mL ether. The organic phases are combined, dried over magnesium sulfate and concentrated to an oily residue. The residue is purified by chromatography on silica gel to give pure 2-(2-chloro-p-tolyl)-4-isopropyl-4-methyl-2-imidazolin-5-thione.

Provenance & Evidence