Action of sodium amalgam on methylene ethers / by Arthur H. Salway.

  • Salway, Arthur H. (Arthur Henry)
Date:
[1910?]
Catalogue details

Licence: In copyright

Credit: Action of sodium amalgam on methylene ethers / by Arthur H. Salway. Source: Wellcome Collection.

    7/10 (page 2417)
    As already explained in the introduction, this substance was found to be /3-5-hydroxy-3-methoxyphenylpropionic acid. fi-5-IIydroxy-3-methoxyphenylpj’opionic acid (III, p. 2415) is readily soluble in ether, alcohol, or hot water, and crystallises from the latter in colourless, hexagonal plates, which gradually become pink on exposure to air. It is insoluble in benzene or light petroleum. Its amide, MeO,CGH3(OII),CH2,CH2*CO,NHo, crys¬ tallises from water in prismatic needles, melting at 126°. In order to prepare the methyl derivative of the above compound, 10 grams of the phenolic acid were dissolved in methyl alcohol and 5 c.c. of methyl sulphate, and 10 c.c. of a 50 per cent, solution of potassium hydroxide added. After the vigorous reaction had subsided, the same quantities of methyl sulphate and alkali were again added, and the mixture heated for a short time on the water- bath. The alkaline liquid was then acidified and extracted with ether, when the ethereal extract yielded an oil which gradually solidified. This product was purified by crystallisation from a mixture of benzene and light petroleum, from which it separated in clusters of colourless, silky needles, melting at 61—62°: 0*1076 gave 0-2490 C02 and 0’0649 H20. C = 631; H = 6‘7. 0*4465 required for neutralisation 2T25 c.c. iV/lO-Na'OH. M.W. = 210. CnII]404 requires C = 62*9; H = 6*7 per cent. M.W. = 210. /3-3 : 5-Dimethoxyphenylpropionic acid, GcH3(Me0)2-CH2-CH2-C02H, is readily soluble in the usual organic solvents, excepting light petroleum. It yields an amide, which crystallises from a mixture of benzene and petroleum in colourless needles, melting at 80—81°. The position of the methoxy-groups in the above compound was ascertained by oxidising a quantity of the substance with a hot alkaline solution of potassium permanganate. At the end of the oxidation, the liquid was cooled, an excess of sulphur dioxide added, and the precipitated oxidation product collected. It was re- crystallised from hot water, when it separated in thin needles, melting at 180—181°. (0*2045 required for neutralisation 11*25 c.c. N/ 10-NaOH. M.W. = 182. Calc., M.W. = 182.) This substance possessed all the properties of 3: 5-dimethoxy- benzoic acid (Biilow and Riess, Ber., 1902, 35, 3901), and was evidently identical with that compound. Reduction of Piperonylacrylic Acid. The reduction of piperonylacryiic acid by means of sodium amalgam was first described by Lorenz {Ber., 1880, 13, 758), who isolated piperonylpropionic acid from the product of the reaction,