DED0012817MA - - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

Registration date: November 26, 1941. Advertised on: September 1, 1955

GERMAN PATENT OFFICE

The subject of patent 887 200 is a process for the production of ω-caprolactam and its derivatives, in which cyclohexanone or analogous ketones are placed simultaneously with an aqueous sodium azide solution in a reaction vessel charged with concentrated aqueous hydrochloric acid at 20 to 30 ⁰ , preferably at 20 to 25 °, can flow in.

It has now been found that with ketones which are caused by the action of the conc. Hydrochloric acid easily suffer a change, works better at temperatures below 20 ⁰ . Such ketones are, for example, 2,2-bis- (4-oxo-cyclohexyl) -propane, dihydroresorcinol and 4-phenylcyclohexanone- (i).

Example ι

A dissolution of 300 g of 2,2-bis- (4-oxo-cyclohexyl) -propane in 1000 ecm chloroform and a Solution of 180 g of sodium azide in 510 ecm of water are concentrated to 3 1 in a four-necked flask with thorough stirring. Hydrochloric acid was added dropwise. The addition of the ketone and the azide solution must be carried out at the same time as possible. The temperature is held up 15 to 20 °. Hydrogen chloride is additionally passed into the hydrochloric acid during the reaction to avoid s to maintain the highest possible H Cl concentration. After the addition has ended, another V2 hour stirred and then added as much water

509 546/28

Claims (1)

D 12817 IVc / 12ρ leads, dal.t the precipitated sodium chloride gellt in solution. The chloroform is separated off and can be purified again by distillation. The hydrochloric acid solution is neutralized by adding soda, with most of the dilatam formed precipitating out. The precipitated substance is filtered off with suction and dissolved by heating with chloroform. The still dissolved portions of the dilatam are extracted by shaking out the neutralized aqueous Li ^{-) SUHg with chloroform.} The combined extracts are dried and almost all of the chloroform is distilled off in a steam bath. Double the amount of acetone is added to the liquid residue while it is still hot and the mixture is stirred. After a short time, the dilaetam begins to crystallize, which is increased by cooling. After suctioning off and washing with acetone or ether, the dilactam of the following constitution is obtained as a white one NH CH ₂ --C CO - CIL-- CH., - CH ₃ CH-C-CH CH, CH, - CIi "- NH CH, - CH, - CO powdery crystals. Yield 268g = 79%. ! By re-evaporation of the acetous and treatment 40 g of an impure product can still be obtained from the residue with ether, which is obtained by recrystallization can be purified from water. The dilactam can be obtained by recrystallization little chloroform, through repeated precipitation from chlorophony solution by ether as well as by Recrystallize from water. At sjn'el 2 In a test arrangement as in Example 1, 750CCI11 hydrochloric acid is introduced. 150 g of 4-Phenyleyclohexanoii- (i) with a (! Content of about 1S ⁰ Ia ketone, which has been obtained by calcium dehydrogenation of the corresponding secondary alcohol, are dissolved in 200 ecm of chloroform and this solution at the same time with a solution of 42 g of sodium azide are added dropwise in 105 cc of water. the temperature is maintained and during the reaction at 15 to 20 ° then for 1 hour at 25 ^0th with addition of ice as much water added, that the cooking salt formed just dissolves. Now, the The chloroform layer is separated off, shaken with soda solution and dried with anhydrous sodium carbonate. After evaporation of the chloroform, the addition of ether gives the lactam in crystallized form. Yield 81 g of j'-phenyl-s-caprolactam after recrystallization from ethyl acetate; mp 153 °. Godparents τ α ν s ρ r υ c η. · Further development of the process for the production of ω-caprolactam and its derivatives according to Patent 887,200, characterized in that temperatures below 20 ^{0 are used} . © 509 546/28 8.