Patent GB-948629-A (GB)
Title: Preparation of acrylates
IPC: C07C69/52
Filed: 1960-03-16
Abstract: Alpha-hydrocarbon substituted acrylic acid esters of tertiary amino alkanols or of 2-(2-pyridyl)-ethanol are prepared by a process comprising (A) initially inter-reacting at an elevated temperature a mixture of an alkanoic acid or an a , b -unsaturated mono-carboxylic acid having a terminal CH2=C< group, nickel carbonyl and acetylene or a mono-hydrocarbon-substituted acetylene or a mono-hydrocarbon-substituted acetylene and (B) introducing into this reacting mixture and reacting therein at an elevated temperature, carbon monoxide, a tertiary amino-alkanol or 2-(2-pyridyl)-ethanol and, if not already present, a mono-hydrocarbon substituted acetylene. The prefered procedure comprises initially reacting together the alkanoic or unsaturated carboxylic acid, nickel carbonyl and a mono-hydrocarbon substituted acetylene, supplying a tertiary amino alkanol or the pyridylethanol, and carbon monoxide to be reacted therein and continuing the reaction by feeding in an organic monocarboxylic acid or hydrochloric acid, and further amounts of nickel carbonyl, carbon monoxide, substituted acetylene, and tertiary amino alkanol or 2-(2-pyridyl) ethanol. Specified tertiary amino alkanols have the general formula <FORM:0948629/C2/1> wherein A represents an alkylene group and R1 and R11 taken individually represent alkyl, cycloalkyl, aralkyl or aryl group or taken together represent a saturated divalent aliphatic chain of 4-5 carbon atoms e.g. tetra-or penta-methylene or 3-oxa-pentamethylene and numerous such compounds are mentioned. The initial reaction (A) produces an acid anhydride. An a :b -unsaturated acid used therein preferably has the formula CH2=C(R)COOH where R is hydrogen, alkyl, cycloalkyl, aralkyl or phenyl and desirably is the same as the substituted acrylic acid whose ester is to be produced; the acid may alternatively be acetic or propionic. In the subsequent reaction stage where a monocarboxylic acid is added it may be acetic, propionic or a substituted acrylic acid. The acid supplied in the subsequent reaction may be equivalent to the nickel carbonyl \sB25% equivalency, the mole ratio of substituted acetylene to total carbonyl may be 1:1\sB20% or more and the amino alkanol may be supplied in amounts equivalent to the total carbonyl \sB at least 10%; preferably not more than 70% of the total carbonyl present is provided by the carbon monoxide.  The reactions may be effected at 65 DEG  to 125 DEG C., if desired in the presence of an inert organic solvent.  The process may be effected batchwise or continuously. The resulting a -substituted acrylic ester may be recovered by distillation of the product mixture preferably in the presence of a polymerization inhibitor e.g., p-hydroxy diphenylamine, N, N1-diphenyl phenylene diamine, di-b -naphthol, hydroquinone or its mono-methyl ether, copper powder, an organic solvent-soluble copper salt, or fumaronitrile. The distillation residue may be worked up to recover the nickel by acidifying with a strong acid to decompose a nickel acrylate present and distilling off the acrylic acid liberated. In typical examples: (1) methacrylic acid, methyl acetylene and nickel carbonyl are fed continuously into a heated toluene solution of methacrylic acid and after reaction has started carbon monoxide and dimethyl amino ethanol are also continuously fed in whereby dimethylamino ethyl methacrylate is formed; (3) as in (1), hydrochloric acid additionally being fed into the reacting mixture; (7) acetic acid, hexyne-1, and nickel carbonyl are fed continuously to a heated mixture of acetic acid in toluene and after reaction has started dimethylamino ethanol and carbon monoxide are also added continuously yielding 2-(N, N-dimethylamino) ethyl a -butyl acrylate. Numerous other esters are specified as obtained by these methods including 1-dimethylamino -2- propyl methacrylate, N-benzyl -N-methylamino ethyl methacrylate, N-phenyl -N- ethylamino ethyl methacrylate and 2-morpholinoethyl methacrylate. The esters may be polymerised or used as stabilisers for fuel oils.ALSO:Substituted polyacrylates are prepared by the polymerization of a -mono-hydrocarbon substituted acrylic acid esters of 2- (2-pyridyl)-ethanol or of a tertiary amino alkanol, particulary one of the general formula: <FORM:0948629/C3/1> wherein A represents an alkylene radical and R1 and R11 taken individually represent alkyl, cycloakyl, aralkyl or aryl groups or together represent a saturated divalent aliphatic chain of 4 or 5 carbon atoms e.g. a tetra- or penta methylene or 3-oxapentamethylene group and numerous such aminoalkanols are specified.  The a -hydrocarbon substituent may be for example a C1- 12 alkyl, cyclohexyl benzoyl or phenyl group. Specified esters include dimethylaminoethyl, dibutylamino ethyl, 1-dimethylamino -2-propyl, N-phenyl- N-ethyl aminoethyl N-benzyl - N - methyl aminoethyl and morpholinoethyl methacrylates, 2-(N,N-dimethylamino)-ethyl a -butylacrylate, 2-(N,N-dimethylamino) ethyl a -decylacrylate and dimethylamino ethyl a -phenylacrylate. Copolymers of these esters are also mentioned. The preparation of the esters is described (see Division C2).