Patent GB-832492-A (GB)
Title: Improvements in the production of acrylic compounds
IPC: C07C51/14
Filed: 1957-04-18
Abstract: Nickel carbonyl, for use as a catalyst in the production of acrylic compounds (see Group IV (b)), may be prepared by treating nickel salt solutions with carbon monoxide at elevated temperature and pressure in the presence of an organic compound which forms with nickel carbonyl a compound in which the carbon monoxide is in a more unstable form than in nickel carbonyl; such organic compounds are those which liberate CO in a solution of nickel carbonyl in ethanolic hydrochloric acid at room temperature; a comprehensive list of such compounds is given (see Group IV (b)). The nickel salts may be of inorganic or organic acids, such as halogen hydracids, sulphuric, nitric, hydrocyanic, carbonic, propionic, butyric and acrylic acids. Solvents such as water, alcohols, acetone and tetrahydrofuran may be used.  Preferred conditions are 50-250 DEG  C. and 50-200 atmospheres.ALSO:Acrylic compounds are prepared by reacting acetylene, carbon monoxide and a compound with reactive hydrogen in an acid medium in the presence of nickel carbonyl at a pressure below 10 atmospheres in the presence of a small amount of an organic compound which forms with the nickel carbonyl a compound in which the carbon monoxide is in a more unstable form than in nickel carbonyl. Compounds with reactive hydrogen include aliphatic, alicyclic, araliphatic and polyhydric and dihydric alcohols (one or more OH groups of which may react), alcohols substituted, e.g. with halogen, ether groups, nitro groups or keto groups, phenols, enols, water and amines.  Suitable organic compounds are those which liberate CO in a solution of nickel carbonyl in ethanolic hydrochloric acid at room temperature; a comprehensive list of such compounds is given, including primary, secondary and tertiary amines and heterocyclic amines containing N in the ring and their onium compounds; tertiary phosphones and their onium compounds; compounds of carbonamide structure, including lactams, and their thio analogues; acid imides; urea and its derivatives; compounds which form inner-complex salts with nickel, such as hydroxy acids and keto acids and their esters; aminoacids; hydroxyaldehydes, hydroxyketones, a -and b -diketones, and the oximes, hydrazones, phenylhydrazones, semi-carbazones and Schiff's bases derived therefrom; azo compounds; compounds with divalent sulphur, such as mercaptans and thio-ethers, heterocyclic sulphur compounds, and disulphides; mono- and polynitriles. Preferred activators include triethylbutyl ammonium bromide or chloride, N-butyl pyridinium chloride, triphenylbutylphosphonium bromide, N-methyl pyrrolidone-2, caprolactam, N,N1-diphenylurea, 1,2-diethyl mercaptoethane, acetylacetone, salicylic acid, thiodibutyric acid, dimethyl formamide and adipic acid dinitrile. Usually 0.1-15% of the activator, based on the weight of the reaction mixture, is used.  The nickel carbonyl may be prepared in situ (see Group III).  The acid medium may be achieved with an acid gas such as hydrogen chloride or an alcoholic or aqueous acid p  solution such as when using hydrogen bromide or iodide or acetic or acrylic acid.  It is possible to use acid-reating compounds which act at the same time as activators, e.g. salicylic, lactic, tartaric and thiodibutyric acids, or enolizable compounds, such as acetyl acetone and benzoyl-acetone.