Bromine → 4-Chlorobenzoyl chloride

Participants

Reaction Steps

To a 25 ml three-necked flask equipped with an equal pressure additional funnel, a dry-ice condenser with a gas outlet and a stopper, is charged 17.9 g (0.1 mole) of 1-chloro-4-chloroformyl cyclohex-1-ene (I). The solution is heated to 90°-100° C. with stirring, using a magnetic stirring bar. Bromine, 32 g (0.2 mole), is added dropwise, sub-surface. The color dissipates quickly and a gas evolution occurs. When about 24 g of bromine has been added, the pot temperature is raised to 120°-130° C. The remaining bromine is added in the same fashion. The pot temperature may then be raised to 150°-160° C. fro 2-4 hours. During this period, an additional amount of bromine, such as about 1-2 g, may be added to complete the conversion of (I). A good yield of 4-chlorobenzoyl chloride will be obtained by the fractional distillation of the mixture.

Provenance & Evidence