DE1224304B - Process for the preparation of an N-acyl-monovinylamine - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

C07c

German class: 12 ο -19/03

Number: 1224 304

File number: F 45437IV b / 12 ο

Filing date: March 6, 1965

Opening day: September 8, 1966

It is known to take acetylene at an elevated temperature in the presence of strongly alkaline catalysts Pressure on carboxylic or sulphonic acid imides that are unsubstituted in the imido group or on carboxylic or sulphonic acid amides, which are substituted on the amide nitrogen by an alkyl or aryl radical to act. According to this process, vinylimides or vinylamides, which apart from the vinyl group have a further Contain alkyl or aryl radical on the acid amide nitrogen, produced (see. German Patent 877 757 and German patent specification 890 508).

The same compounds are obtained according to the method of US Pat. No. 2,231,905, that is the thermal elimination of acetic acid from N - (/ S-acetoxyethyi) ~ substituted dicarboximides or from N- (j3-acetoxyethyl) -substituted carboxamides, which also contain a further alkyl or carry aryl radical on the acid amide nitrogen describes. In column 1, lines 38 to 45 of this patent specification it should be noted that in the pyrolysis of N - (/? - Acetoxyäthyl) -carbonsäureamiden, which still contain a hydrogen atom on the carboxamide atom, oxazolines, as ring-shaped compounds, develop.

The present invention relates to a process for the preparation of an N-acyl-monovinylamine, characterized in that from an N-acyl-1-amino-1-cyanoethane of the general formula CH ₃ -CH (CN) -NHR, where R is a Acyl radical means thermally splitting off hydrogen cyanide in the presence of solids.

The thermal cleavage, explained using a special example, proceeds in the sense of the following reaction:

CH ₃ - CH - NH - C - H

Method of making a
N-acyl monovinylamine

CN O
> CH ₂ = CH - NH - C - H + ■ HCN

The starting materials to be used for the process according to the invention, the N-acyl derivatives of 1-amino-l-cyanoethane, are made by known processes from oc-amino-propionitrile, which in turn is easily and quantitatively obtained from acetaldehyde, hydrogen cyanide and ammonia by acylation in yields of over 90 percent by weight, based on α-amino-propionitrile. To be used for acylation the usual agents such as carboxylic acid halides, carboxylic acid anhydrides, carboxylic acid esters, or im special case of acetylation also ketene is used.

Applicant:

Paint factories Bayer Aktiengesellschaft,

Leverkusen

Named as inventor:

Dr. Peter Kurtz, Leverkusen;

Dr. Hans Disselnkötter, Cologne-Stammheim

The inventive method can be performed such that the N-acyl derivatives of 1-amino-l-cyanäthans in liquid, but preferably in the vapor phase in a introduced at 250 to 75O ⁰ C, preferably at 450 to 65O ⁰ C, heated reaction tube , which is filled with solids, for example made of glass, quartz, iron, silicon carbide, aluminum fluoride, coke, lithopone, calcium phosphate, alumina, to enlarge the reaction surface.

It is advantageous to use an inert carrier gas such as nitrogen, hydrogen or argon at the same time. The pyrolysis can, for. B. under normal pressure or under reduced pressure, preferably at 1 to 100 Torr. The preferred embodiment of the method according to the invention is carrying out the pyrolysis under reduced pressure. The vaporous ones leaving the reaction tube Pyrolysis products or the unreacted starting products are with the help of condensed suitable cooling systems and then subjected to a fractional distillation. The at Hydrogen cyanide resulting from pyrolysis, which is obtained as the first fraction, is used again for production of the starting material used. The subsequently passing N-acyl-vinylamines fall into excellent purity and excellent yields of over 80 percent by weight, based on pyrolyzed N-acyl derivatives of 1-amino-l-cyanoethane. The distillation residue that is not pyrolyzed Contains starting material, can be used directly or after purification z. B. by distillation or recrystallization are again subjected to thermal cleavage.

The process according to the invention can be carried out batchwise or continuously.

The N-acyl-vinylamines obtained are valuable starting materials for the production of high-mol-

609 659/431

3 4

connections. The N-formyl pump, which is easily accessible after the trap, cooled to −80 ° C. according to the invention, is connected to a water jet method vinylamine was not previously known. weak nitrogen atom passed through the apparatus.

The apparatus used in Example 1 as the starting material for the during the thermal cleavage

Process according to the invention used N-formyl-5 under a pressure of 20 torr. At the end of the

1-amino-l-cyanoethane is obtained as follows: The sample flask contains 193 g of reaction ^

In an autoclave, the a-amino product in the form of almost colorless crystals of the enamel

Propionitrile excess. Formic acid methyl ester point 47 ° C, in the cold trap there are 69 g of one

pumped and the mixture for 4 hours at 100 ° C mixture of hydrogen cyanide and benzene with a

heated. The car coolant will then have a fractional content of 48 g hydrocyanic acid (= 80 percent by weight

tioned distilled. After distilling off the methanol of theory). The distillation of the crystallized

and the formic acid reaction product used in excess gave at 68 to 75 ⁰ C below

esters is the N-formyl-l-amino-l-cyanoethane at 0.6 Torr 133 g (= 70 percent by weight of theory)

115 to 130 ° C and a pressure of 0.2 Torr in an N-acetyl-vinylamine, F. = 53 ⁰ C. - - -

Yield of over 90 percent by weight obtained; 15 The distillation residue of 57 g consists of almost

«!," = 1.4550. -R-r-Ir ■ _: .-. \ -; pure starting material.

Example 1 ^ * ^e Yield of N-acetylvinylamine, based on

pyrolized N-acetyl-1-amino-1-cyanoethane is

The apparatus for "thermal fission consists of 91 percent by weight of theory. ...

from a heatable vertical quartz tube of 3 cm 20. ·. ".-_ · '·

Diameter and 56 cm length, the one with quartz piece -'- 'Example i ... - _;

is filled. At the upper end of the reaction ■ In the same apparatus as in Example 2 was

tube is a drip funnel, on the lower 342 g of N - butyryl -1 - amino -1 - cyanethane: inside

End a cooler with a template that split a deep 5.7 hours at 600 ° C. The yield at

is downstream of the cold trap. The apparatus is eva- 25 crude product was 267 g. The distillation provided

cuttable. ..,., ... '"'" * '165 g (· = 60 percent by weight of theory) of pure

The apparatus is evacuated to 5 torr and on n-butyryl-vinylamine, mp = 36 ° C, bp. _0j4 = 70 bis

about 600 * C heated 'Over the course of 3 hours, 8O ⁰ C, in addition to 57 g (= 17 percent by weight of theory)

through the top of the tube 300 g of N-formyl-1-aemino starting material. In relation to split initial

1-cyanethane added. The material from the lower end of the pipe 30 is the yield of N-butyrylvinylamine

escaping vaporous fission products or ■ - 72 percent by weight. ■ - ■ - · .- ·

the unreacted starting material is replaced by the · -. · '{A

Cooling device cooled and condensed. / ^ 'Example 4.

45 g of cyanide are from the deep freeze. In the same apparatus as in Example 2, substance = 54.5 percent by weight of theory, based on 35 50 g of N-benzoyl-1-amino-1-cyanoethane with ¹ addition of N-formyl-1 -amino-l-cyanoethane, isolated. The In- ^c of 10 ml of benzene from a steam-heated hold of the template is 250 g and is added dropwise to a frak ^ - dropping funnel within 1 hour. The subjected to ionized distillation. Under a pressure of 600 ⁰ C and executed under nitrogen pyrolysis of 12 Torr distilled at 85 to 86.5 ° C 100.2 g provided 37 g of a solid crude product. In addition, N-Formylvinylamin = 46 weight percent of the Theo ^1-40 were performed in a cold store 11.6 g of a condensate rie, based on N-formyl-l-amino-l-cyanäthan over. The next fraction is 128 g of pure extract, 4.6 g, that is 59% of the theoretically cleavable starting material, N-formyl-l-amino-l-cyanoethane, of the amount was determined. From the crude product refractive index n% ° = 1.4550. The N-formyl vinyl was obtained by distillation (120 ° C / 0.3 Torr) 10 _{5 5} g of _{amine, b.p. 12} = 85 to 86.5 ° C, n ² g = 1.4940, has 45 N-benzoyl vinylamine (= 25 percent by weight of the following analysis data: rie). The residue yielded, from benzene, um analyzes calculated for C ₃ H ₅ NO; Molecular weight 71.08. Installed, I ₈ g of starting material. Based on the

Bererhnpt r 50 fiQ π 7 09 N 1Q 71 O ?? 510 / · raw material consumed. In relation to the

Calculated ... C 50.69, H 7.09, N 19.71, O 22.51 / ₀ , _{starting material required} is thus the yield

found ... C 50.40, H 7.04, N 19.56, O 22.64 "/". _{5o aQ N. Benzo} ^S _ylv f _nylamine 39 percent by weight of

The constitution results from the IR spectrum: - Theory.

NH stretching vibration at 3250 cm " ¹ (strong), CO at _R · ·,,

1675 cm- ¹ (very strong), double bond 1640 cm- ^{1 p}

(very strong), NH deformation 1510 cm " ¹ (medium), end- By the same. apparatus as in Example 2

permanent vinyl group 862 cm " ¹ (medium) 975 cm- ¹ 55 are 50 g of NS-chlorobenzoyl-1-amino-1-cyanoethane

(middle). Taking into account the regained (F. = 108 ° C) within 30 minutes at 500 ° C / 12 Torr

NEN shares of N-formyl-1-amino-1-cyanoethane replaced. The raw yield is 37 g = 85%

give the following yields for the cleavage products: the theory. Recrystallization from tetrachloride

N-formyl-vinylamine 80.5%> Hydrogen cyanide 95%. carbon supplies pure N-3-chlorobenzoylvinylamine,

_. · ■ 1 9. 60 F. = 121 ⁰ C, its structure by analysis as well

ebeispieli infrared and nuclear magnetic resonance spectrum is confirmed.

A mixture of 250 g of N-acetyl-1-amino-1-cyano-. .

Ethane and 25 ml of benzene are extracted from steam

heated dropping funnel in a 100 g of N- [α-naphthoyl] -l-amino-l-cyanoethane within 150 minutes Vertical standing filled with quartz shards and 65 (F. = 138. to 139.5 ° C) are melted and out

over a length of 62 cm to 600 ⁰ C heated por- 'a heatable dropping funnel within 235 minutes

cellan pipe dripped in. A cooled by a vertical, with serves as a template. Quartz shards

Glass flask, which is filled with a reflux condenser and a length of 62 cm to 600 ⁰ C ^

Irish heated stainless steel pipe under a pressure of 16 Torr. At the end of the experiment, 81 g (= 91% of theory) of a brown mass interspersed with crystals, which represents the reaction product, have accumulated in the receiver, while the freezer trap contains 12 g (= 100% of theory) hydrogen cyanide. 10 g of the reaction product are distilled. The portions (1.5 g) passing over between 50 and 180 ° C./0.3 Torr solidify in the original. These crystals are repeatedly recrystallized from cyclohexane, m.p. = 118 ⁰ C. make on analyzes of IR and NMR spectra N- [a-naphthoyl] -N-vinylamine represents.

Claims (2)

Patent claims: 1. Process for the preparation of an N-acylmonovinylamine, characterized by the fact that an N-acyl-1-amino-1-cyanoethane the general formula CH ₃ - CH (CN) - NHR, where R denotes an acyl radical, thermally splitting off hydrogen cyanide in the presence of solids. 2. The method according to claim 1, characterized in that one carries out the thermal cracking at 450 to 65O ⁰ C. 609 659/431 8.66 © Bundesdruckerei Berlin