Methane → Caprolactam

Participants

Reaction Steps

The ODCB solution of N-benzoyl-α-chloro-ε-caprolactam is passed through a charcoal bed to remove tars as impurities. It is then passed into another reaction vessel where 9718 parts (86 mols) of ε-caprolactam are added. The transamidation is conducted by heating and stirring the ODCB solution at 140° C. for 2 hours. The solution is then cooled to 5° C. for 1 hour whereupon 21,000 parts (82 mols) N-benzoyl-α-chloro-ε-caprolactam precipitates out of the solution. The N-benzoyl-α-chloro-ε-caprolactam is filtered off and saved for recycle. The ODCB solution is then extracted with 250,000 parts 8 weight percent aqueous hydrochloric acid to remove α-chloro-ε-caprolactam and residual ε-caprolactam. The aqueous hydrochloric acid is then extracted countercurrently with 250,000 parts chloroform, and the chloroform extract evaporated to yield 10,915 parts (74 mols) of α-chloro-ε-caprolactam and 1356 parts (12 mols) of ε-caprolactam. The ε-caprolactam is separated from the α-chloro-ε-caprolactam by fractional distillation under vacuum and recycled to the transamidation step.

Provenance & Evidence