N-(Phenylthio)phthalimide

Preparation

(a) Preparation of benzenesulfenyl chloride. To a stirred solution of 55 gm (0.5 mole) of benzene thiol in 300 ml of η -pentane at 0°C is added chlorine gas until an assay (GC) of the resulting red-orange solution shows quantitative conversion to the sulfenyl chloride. The reaction usually re­quires about 39 gm (0.6 mole) of chlorine.
(b) Reaction of benzenesulfenyl chloride with phthalimide. To a stirred solution of 73.5 gm (0.5 mole) of phthalimide in 200 ml of dimethylforma-mide is first added 60 gm (0.6 mole) of triethylamine. Then the sulfenyl chloride solution from (a) is slowly added dropwise. The reaction mixture is stirred for \ hr, poured into 2 liters of cold water, filtered, and dried to afford 121 gm (95%), m.p. 160-161°C (recrystallized from ethanol).
Complex imides such as camphorimide and 9,10-dihydroanthracene-9,10-endo-a,/3-succinimide have been alkylated in methylene dichloride with alkyl halides, using tetrabutylammonium bromide as a phase-transfer catalyst and aqueous potassium hydroxide as a base.