Patent GB-733097-A (GB)
Title: Improvements in or relating to a process for preparing acrylamides
IPC: C07D295/182
Filed: 1952-12-30
Abstract: Acrylamides are prepared by reacting at a temperature between 0 DEG and 75 DEG  C. acetylene, nickel carbonyl, an aliphatic carboxylic acid containing not more than 4 carbon atoms and an amine having hydrogen on the amino nitrogen atom thereof, and while this reaction is taking place, introducing carbon monoxide into the reaction mixture and maintaining the reaction mixture at a temperature between 0 DEG  75 DEG  C.  The carbon monoxide introduced into the reaction mixture may be from 20 to 80 per cent of the total quantity of carbon monoxide used in the reaction, i.e. the added carbon monoxide and the carbon monoxide available in the nickel carbonyl.  Sufficient acid may be used to form a nickelous salt with all the nickel available in the nickel carbonyl, the molar quantity of acetylene being within 10 per cent of the equivalent quantity of the total carbon monoxide available.  Suitable aliphatic acids for use in the above process are acetic, propionic, butyric, acrylic and methacrylic acids.  A large number of amines are referred to in the Specification and are of the formula R1R2NH wherein R1 and R2 represent aliphatic, cycloaliphatic, arylaliphatic, aryl or heterocyclic radicals, or R1 and R2 together may form a divalent chain, and one of R1 and R2 may represent hydrogen, and polyamines, the preferred amines being aniline, N-methylaniline, 2-vinyloxyethylamine, n-butylamine and morpholine. The process may be carried out in a continuous manner by reacting acetylene, nickel carbonyl, acrylic acid and the amine and while these are reacting adding to the reacting mixture acetylene, carbon monoxide, acrylic acid and said amine, the carbon monoxide supplying between 50 per cent and 70 per cent of the total carbon monoxide available, the acid being in a quantity equivalent to the nickel to form nickel acrylate and the acetylene being supplied in a molar excess of the total cabon monoxide.  An alternative method of carrying out the process in a continuous manner is to react at a temperature from 35 DEG  to 60 DEG  C., acetylene, nickel carbonyl, acrylic acid and a primary or secondary amine, the acid being at least equivalent to the amine, and while this reaction takes place acetylene, carbon monoxide, acrylic acid, nickel carbonyl and said amine are added to the reacting mixture, the reaction temperature being maintained from 35 DEG  to 65 DEG  C., the carbon monoxide supplying between 50 and 70 per cent of the total carbon monoxide available, the amine being supplied in a molar excess of the total carbon monoxide available, the molar quantity of acetylene being equivalent to the total p  carbon monoxide within 10 per cent, the reaction mixture is taken off and acrylic acid added in an amount at least equivalent to any nickel carbonyl in the reaction mixture to form nickel acrylate and the reaction mixture is then treated with acetylene to react with the remaining nickel carbony.  In the examples the following compounds are prepared: N-phenylacrylamide, N-n-butylacrylamide, N-(2-vinyloxyethyl) acrylamide, N-(b -hydroxyethyl) acrylamide (N-(b -acryloxyethyl) acrylamide is also formed), N,N1-ethylenediacrylamide N-alkylamides where the alkyl groups contain 12/15 carbon atoms, and N-methyl-N-phenylacrylamide. The following compounds are also mentioned: N-isopropyl-, N-sec.-butyl-, N.-tert.-butyl-, N-n-dodecyl-, N-cyclohexyl-, N-morpholino-, N,N-di-(2-ethylhexyl)-, N,N-diethyl-, N-methyl and N,N-dimethyl-acrylamide.