2808.     REPPE, -----.  New Synthesis of Acrylic Acid.  Modern Plastics, vol. 23, No. 3, 1945, pp. 162-165, 210; Chem. Abs., vol. 40, 1946, p. 1449.

        Translation of a captured German report by the above author, obtained under auspices of U. S. War Department.  Metal carbonyls promote reaction between C2H2 or olefins, CO and H2O, alcohols, or other compounds containing labile H.  Cyclopropenones or cyclopropanones probably form as intermediates by interaction between C2H2 or olefin and CO.  These intermediates hydrolyze or alcoholyze to the corresponding acids or esters.  Acrylic esters or amides are obtained from C2H2, CO, and alcohol or amine with Ni and NiI2 catalyst at 150.  Similarly, olefins with CO and alcohols give almost quantitative yields of saturated carboxylic acid esters, a-olefins yield a mixture of straight chain and a-Me substituted acid esters.  The Oxo synthesis of aldehydes also is explained as owing to hydrogenolysis of a cyclopropanone intermediate.  Ni(CO)4 (0.25 mol.) added dropwise to a mixture of EtOH (1 mol.) and concentrated HCl (0.5 mol.) saturated with C2H2 gives CH2:CHCO2Et virtually quantitatively.  Similarly other alcohols give the corresponding acrylate esters, mercaptans give acrylic thio esters, amines give acrylic amides, and H2O gives CH2:CHCO2H, all yields being substantially quantitative.  Co carbonyl, but not Fe carbonyl, may replace Ni(CO)4 in this reaction.  NiCl2 solution resulting from the process is reclaimed by adding NH3 in slight excess over the requirement to form NiCl2 hexamine and treating with CO at 80 and 50-100 atm. to form Ni(CO)4.

           RESCORLA, A. R.  See abs. 3082.