DE1239689B - Process for the production of epsilon-caprolactam - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

C07d

German class: 12p -5

Number: 1239 689

File number: M 41688IV d / 12 ρ

Filing date: June 2, 1959

Open date: May 3, 1967

In British patent specification 743 246 there is a process for the preparation of 6-aminocaproic acid derivatives (mainly esters and lactams) by catalytic hydrogenation of 5-cyano-penteno (3) acid esters in the presence of Raney nickel or Raney cobalt at elevated temperatures and elevated Pressure described with subsequent fractional distillation.

This well-known hydrogenation of the 5-cyano-pentenoic (3) acid esters mainly gives aminocaproic acid esters:

ROOC - CH ₂ - CH = CH - CH ₂ - CN + 3 H ₂

-y ROOC - (CHa) ₅ - NH ₂

In reworking the known process, 40% of the aminocaproic acid esters were used ε-caprolactam obtained. Gets ε-caprolactam one also by known processes in which (5-cyanovaleric acid ester in the presence of organic Solvents and hydrogenation catalysts are treated with hydrogen at elevated temperature. However, the yields of ε-caprolactam are also not high in these processes.

It has now been found that the process for the preparation of ε-caprolactam by Treatment of a 5-cyanopentene (3) acid ester with hydrogen in the presence of a catalyst elevated temperatures and pressure the e-caprolactam in high yields (80 to 90%) obtained when the solution of an alkyl 5-cyano-pentene (3) acid ester in an ether and / or Alcohol in the presence of a mixed catalyst composed of Raney nickel-chromium and sodium hydroxide solution or Raney nickel-cobalt or Raney palladium cobalt and ammonia with the hydrogen first at temperatures between 80 and 120 ° C and then treated at temperatures between 200 and 240 ° C.

The inventive method represents a considerable technical advance because that The end product of the reaction consists only of ε-caprolactam, whereas z. B. from the British patent 743 246 known processes, as already mentioned, mainly aminocaproic acid esters are formed.

example 1

139g5-cyanopentene (3) acid methyl ester, 1600 ecm 2 g n-butyl alcohol containing dissolved sodium hydroxide and 4 ecm of Raney nickel-chromium soaked with butyl alcohol are 30 minutes at 80 to 100 ° C and 60 to 100 atm. with hydrogen in one

Process for the production of ε-caprolactam

Applicant:

MONTECATINI Societä Generale per
rindustria Mineraria e Chimica,
Milan (Italy)

Representative:

Dr. Dr. J. Reitstötter, patent attorney,
Munich 15, Haydnstr. 5

Named as inventor:

Francesco Minisci,

Guiseppe Cantatore,

Giocchino Boffa, Milan (Italy)

Claimed priority:
Italy 6 June 1958 (8744)

Treated rotary autoclave and then heated to 240 ° C for 3 hours. After the catalyst and the solvent have been separated off, 94 g of ε-caprolactam are distilled; Bp ₁₆ = 148 to 149 ° C, bp ₁₂ == 139 ° C; Yield 83%.

Example 2

130g5-cyano-pentene (3) -säuremethylester, 1200 cc of 6.25 g of an aqueous 32% sodium hydroxide solution containing methyl alcohol and 4 cc of methanol soaked with Raney-nickel chromium for 30 minutes at 9O ⁰ C and 60 to 100 Atm . treated with hydrogen in a rotary autoclave; then ecm of dioxane are added and the methanol is distilled off. The remaining solution is then heated to 230 ° C. for 3 hours; the solvent is removed and 91.5 g of ε-caprolactam are distilled off; Bp _ie = 148 to 149 ° C, bp ₁₂ = 139 ° C; Yield 81%.

Example 3
50

139g5-cyanopentene (3) acid methyl ester, 1600 ecm dioxane, 2 ecm Raney nickel in dioxane, 2 ecm Raney

709 578/315

10

Cobalt and 45 g of anhydrous ammonia are 1 hour at 90 to 110 ° C and 70 atm. treated with hydrogen in a rotary autoclave; the ammonia is then removed and the mixture is heated to 220-225 ° C. for 5 hours. After the solvent has been separated off, 99.5 g of ε-caprolactam are distilled off; Bp ₁₆ = 148 to 149 ° C, bp ₁₂ = 139 ° C; Yield 88%.

Example 4

139 g of methyl 5-cyano-pentene (3) acid, 1600 ecm of dioxane, 2 ecm of Raney cobalt, 4 g of palladium-calcium carbonate (1.36% palladium) and 45 g of anhydrous ammonia are heated to 90 to 110 ° C. for 1 hour and 75 atm. treated with hydrogen in a rotary autoclave; the ammonia is then removed and the mixture heated to 210-230 ° C. for 5 hours. After the solvent has been separated off, 150 g of ε-caprolactam are distilled off; Bp ₁₆ = 148 to 149 ° C, bp ₁₂ = 139 ° C; Yield 89%.

Claims (1)

Claim: Process for the preparation of e-caprolactam by treating a 5-cyano-pentene (3) acid ester with hydrogen in the presence of a catalyst at elevated temperatures and elevated temperatures Pressure, characterized in that the solution of a 5-cyano-pentene (3) acid alkyl ester in an ether and / or alcohol in the presence of a mixed catalyst made of Raney nickel-chromium and sodium hydroxide solution or Raney nickel-cobalt or Raney palladium-cobalt and Ammonia with the hydrogen first at temperatures between 80 and 120 ° C and then treated at temperatures between 200 and 240 ° C. Considered publications:
German Patent Nos. 915 568, 765 203;
British Patent No. 743,246;
Annalen der Chemie, Vol. 596, 1955, p. 127. 709 578015 4.67 © Bundesdruckerei Berlin