DE1234729B - Process for the preparation of 3-chlorocaprolactam - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. CL:

C07d

German class: 12p-5

Number: 1234 729

File number: M 55396IV d / 12 ρ

Filing date: January 11, 1963

Opened on: February 23, 1967

The invention relates to an improved process for the production of 3-chlorocaprolactam.

It is known from German Auslegeschrift 1115 257 to produce 3-chloro-£ -caprolactam in such a way that one ε-caprolactam successively with phosphorus oxychloride, phosphorus pentachloride and sulfuryl chloride treated, the resulting α, α-dichloro-ε-caprolactim chloride decomposed with water and the obtained «, a-dichloro-s-caprolactam in the presence catalytically hydrogenated by Raney nickel.

It was found that S-chlorocaprolactam itself Can be produced with a better yield based on ε-caprolactad by adding N-benzoyl-3-chlorocaprolactam with sulfuric acid, the sulfuric acid content of which is at least 90%, at temperatures not treated above 50 ° C., the reaction mixture is treated with water, the aqueous solution alkaline, the product is extracted with a water-immiscible solvent and the Evaporated solvent extract. ao

In the implementation, the use of technical concentrated sulfuric acid with a Sulfuric acid content of about 93.5% is preferred because the highest yields of the desired Product obtained when the reaction is carried out with this acid. But you can also do others concentrated sulfuric acids containing at least 90% sulfuric acid, or fuming sulfuric acid Use (oleum) in the process according to the invention.

The process is conveniently carried out by adding the N-benzoyl-3-chlorocaprolactam the sulfuric acid is added and the reaction mixture is left to stand until the reaction has ended.

Any base can be used to neutralize the aqueous solution of the reaction mixture use; however, it is generally preferred to work with an inorganic base, such as a Alkali hydroxide or ammonium hydroxide. Suitable, water-immiscible solvents for Extract the S-chlorocaprolactam from the aqueous alkaline solutions are chloroform, benzene, toluene and the like.

Process for the production of
3-chlorocaprolactam

example

100.4 g of N-benzoyl-S-chlorocaprolactam will be added with stirring to 140 ml of concentrated sulfuric acid, the temperature being kept below 25 ° C will. The mixture is stirred for 1 hour without external heating (the temperature being increased to 38 ° C Applicant:

Merck & Co., Inc., Rahway, N. J. (V. St. A.)

Representative:

Dr.-Ing. W. Abitz and Dr. D. Morf,

Patent Attorneys, Munich 27, Pienzenauer Str. 28

Named as inventor:

Roger James TuIl, Plainsfield, N.J. (V. St. A.)

Claimed priority:
V. St. v. America January 29, 1962
(169 655)

increases) and then heated to 50 ° C for 2 hours. The mixture is then cooled to 25 ° C and up kg of a mixture of ice and water poured. The mixture becomes 28% by adding 400 ml Ammonium hydroxide solution made alkaline, keeping the temperature below 20 ° C, and then extracted three times with 500 ml of chloroform each time. The chloroform extracts are combined and evaporated. 56.2 g of 3-chlorocaprolactam are obtained. Mp 91.5-94 ° C; Yield: 95.3%.

Claims (1)

Claim: Process for the production of 3-chloro-ε-caprolactam, characterized in that N-benzoyl-S-chloro-s-caprolactam with Sulfuric acid, the sulfuric acid content of which is at least 90%, not at temperatures Treated above 50 ° C, the reaction mixture mixed with water, the aqueous solution alkaline makes, extracted with a water-immiscible solvent and the solvent extract evaporates. Considered publications:
German Auslegeschrift No. 1115 257;
Patent Specification No. 3,996 of the Office for Inventions and Patents in the Soviet Zone of Occupation in Germany; U.S. Patent No. 2,877,220.