PATENTS

2823.   ROGERS, D. C.  (G. D. Buckley, F. S. B. Jones, W. J. Levy, and Imperial Chemical Industries Ltd.).  Ketenes, Carboxylic Acids,   and Their Derivatives.  British Patent   668,309,  Mar. 12, 1952.  Chem. Abs., vol. 47, 1953,   p. 1183.

            C₂H₂ derivatives are oxidized with N₂O at 200°-300° and 100-500 atm. pressure.  Oxidation in the presence of N₂O alone gives ketenes, usually in the form of dimers of uncertain constitution; in the presence of H₂O, NH₃ or primary or secondary amines, carboxylic acids, alcohols, or phenols; in the presence of mercaptans or H₂S, carboxylic acids, amides, acid anhydrides, esters, thio esters, or thio acids.  1-Hexyne 10 parts and EtOH 40 parts are placed in a reactor double the volume of the reactants, the air is replaced by N₂O, the reactor heated to 300°, N₂O pumped in to 500 atm., and the mixture stirred 1 hr., yielding 15 parts AmCO₂Et.  C₂H₂ 15 parts and EtOH 30 parts at --40° similarly treated yield an azeotrope 12 parts, boiling 71°, containing EtOAc 70% and EtOH 30%.  HOCH₂CH₂C:  CH 5 parts in cyclohexane 35 parts gives γ-butyrolactone 5 parts;    PhC:  CH  10 parts in H₂O 30 parts gives  PhCH₂CO₂H.

                        RHM & HAAS Co.   See abs. 1854, 1855, 2206, 2207, 2208, 2209.