Chlorine → N-Chlorophthalimide

Participants

Reaction Conditions

Reaction Steps

To 800 ml. of methylene chloride were added 50 grams (270 mmoles) of potassium phthalimide. The resulting slurry was chilled to 0° C. To a jacketed flask maintained immediately above the main reaction vessel were added 200 ml. of methylene chloride. The methylene chloride was saturated with chlorine and was maintained at a temperature of -5° C. to 0° C. The flask containing the chlorinesaturated methylene chloride was equipped with a dry-ice trap to ensure that none of the reagent escaped. The chlorine-saturated methylene chloride then was added to the potassium phthalimide mixture as rapidly as possible by means of a tube which extended below the surface of the potassium phthalimide slurry. Addition was completed in less than 30 seconds. During addition, the temperature of the mixture increased from 0° C. to 10° C. The resulting mixture had a greenish-yellow color which persisted. The mixture was allowed to warm to 20° C. over a two hour period. Some undissolved lumps of potassium phthalimide were noted in the mixture. The resulting potassium chloride percipitate was removed by filtration, and the filtrate was evaporated in vacuo to a slush. Heptane (about 400 ml.) was added, and the mixture was filtered. The collected N-chlorophthalimide was reslurried in about 500 ml. of water and vacuum-dried to afford 42.9 grams (88% yield) of N-chlorophthalimide.

Provenance & Evidence