DE1060379B - Process for the preparation of acid amides from nitriles - Google Patents

Description

C O 7 C 2 3 1 / O 6

FEDERAL REPUBLIC OF GERMANY

GERMAN

kl. 12 ο 16 ? "/,

INTERNAT. KL. C 07 C

PATENT OFFICE

EXPLAINING EDITORIAL 1060 379

B 47342 IVb / 12 ο

REGISTRATION DATE: J A N U A R 1958

NOTICE
THE REGISTRATION
AND ISSUE OF THE
EDITORIAL:

JULY 2, 1959

It is known to hydrolyze nitriles by gentle hydrolysis, e.g. B. in the presence of alkaline hydrogen peroxide, Mineral acids or by using basic ion exchangers, in the appropriate To transfer acid amides. In this process, however, in addition to the acid amides, unsaponified ones are also obtained Proportions, sometimes also free acids or their salts as by-products depending on the type of saponification, together with the non-volatile catalysts by cumbersome methods from the reaction process must be separated.

It has now been found that nitriles can be converted into the corresponding nitriles in a simple manner and in very good yields Acid amides can be converted if one is aliphatic, cycloaliphatic or arylaliphatic Nitriles treated with water in the presence of ammonium sulfide at elevated temperature.

The following equation shows the course of the reaction:

RCN

H ₉ O

80--100 °

rc;

, 0

NH,

In this, R denotes an alkyl, cycloalkyl or aralkyl radical, the nitrile group being added to the latter the alkyl radical is bonded.

All saturated nitriles, d. H. aliphatic, cycloaliphatic and alkyl aromatic nitriles in which the nitrile group is bonded to the alkyl radical in very good yields can be saponified to the corresponding acid amides. Examples are: Acetonitrile, propionitrile, butyric acid nitrile, the nitriles of fatty acids, such as stearic acid nitrile, or the nitriles of dicarboxylic acids, such as succinic acid, adipic acid, suberic acid dinitrile and benzyl cyanide and Phenylbutyronitrile. The process is generally carried out at an elevated temperature, e.g. B. at temperatures up to 100 ° C. It is expedient to work between 70 and 100 ° C. It is advantageous to work in the process under pressure, e.g. B. by combining the starting materials with the catalyst Ammoniumsulftd used heated in a closed vessel. However, you can also inert Gases, e.g. B. nitrogen and hydrogen. When performing the procedure under pressure temperatures above 100 ° C can also be used. In general, the saponification takes place in a short time Completely. There are neither by-products nor unsaponified fractions.

Ammonium sulfide is used as the catalyst for the saponification. It does not matter whether the ammonium sulfide as such or in the form of its method of production
of acid amides from nitriles

Applicant:

Aniline & Soda Factory in Baden

Corporation,

Ludwigshafen / Rhine

Dr. Harry Distler, Ludwigshafen / Rhine,

and Dr. Nicholas v. Kutepow, Karlsruhe-Rüppurr,

have been named as inventors

Components, d. H. Ammonia and hydrogen sulfide are added to the aqueous solution of the starting materials will.

Water is used as a solvent or suspending agent. But you can also use other solutions. Diluents such as B. alcohols, ethers, Use thioethers or acid amides. The ammonium sulfide solution is generally in a

Concentration up to 25%, expediently 5 to 10%, used.

The parts mentioned in the examples are parts by weight.

35

example 1

50 parts of adiponitrile are mixed with 100 parts of a 10% aqueous ammonium sulfide solution Shaken at 100 ° C for 10 hours. The resulting adipic acid amide separates into one Quantity of 58 parts (corresponding to 88% of theory) and is filtered off. After recrystallization from water, it has a melting point of 224 to 226 ° C.

45

Example 2

50 parts of benzyl cyanide and 100 parts of a 10% strength aqueous ammonium sulfide solution are 10 hours heated to 100 ° C for a long time with vigorous shaking. After cooling down, this decides standing phenylacetamide in an amount of 54 parts; corresponding to a yield of 92% of the Theory. After a single recrystallization from water, the phenylacetamide has a melting point of 156 up to 158 ° C.

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Example 3

50 parts of succinic acid dinitrile are mixed with 100 parts of a 10% strength aqueous ammonium sulfide solution as in Example 1 implemented. This produces 56 parts of succinic acid diamide, corresponding to a yield of 78% the theory. After filtering off and recrystallizing from water with a slight The addition of glacial acetic acid melts the succinic acid diamide obtained at 246 ° C.

Example 4,

50 parts of suberonitrile are mixed with 100 parts of aqueous 20% ammonium sulfide solution for 10 hours treated at 100 ° C in the containment vessel. 58 parts of suberic acid diamide are obtained after recrystallization twice obtained from water. The yield is 92% of theory. F. 216 ° C.

J- j ')' u 3 Ck B e i s ρ i e 1 5

50 parts of benzyl cyanide are mixed with 50 parts of water and 50 parts of ammonium polysulfide for 10 hours 100 ° C treated in the containment vessel. The resulting phenylacetamide (52 parts) is filtered off and melts after recrystallization from water in the form of colorless crystals at 156 ° C.

Claims (2)

Patent claims: 1. Process for the preparation of acid amides from nitriles, characterized in that one aliphatic, cycloaliphatic or araliphatic nitriles with water in the presence of ammonium sulfide treated at elevated temperature. 2. \ ^ experience according to claim 1, characterized in that that the implementation is carried out under pressure. © 909 559/436 6.