Derivatives of gallic acid / by Frederick B. Power and Frank Shedden.

  • Frederick Belding Power
Date:
[1902.]
Catalogue details

Licence: In copyright

Credit: Derivatives of gallic acid / by Frederick B. Power and Frank Shedden. Source: Wellcome Collection.

    8/12 (page 78)
    On treating the diazo-compound with stannous chloride in cold hydrochloric acid, considerable effervescence was produced and it became completely dissolved. After removing the tin by hydrogen sulphide, the products of the reaction were found to be ammonium chloride and ethyl gal late. The production of ethyl gallate from this diazo-compound will serve to explain the formation of the monoamino- ester by the reduction of ethyl dinitrogallate (p. 76). Hydrochloride of Ethyl Diaminogdilate, C6(NH2)2(0H)S-C02C2H6,2HC1. This substance, as obtained in the manner already described, forms a fine, crystalline powder of a light brown colour. By redissolving it in hot absolute alcohol (in which it is somewhat sparingly soluble) and adding ethyl acetate it becomes much lighter in colour, but when kept shows a tendency to darken. The alcoholic solution rapidly assumes a pink hue. It is very easily oxidised. It dissolves readily in water, but the solution almost immediately becomes blue, and, on standing, blue flakes are deposited. The blue colour is intensified by the cautious addition of ferric chloride, but is destroyed by adding an excess. If the solution in water be acidified with hydrochloric acid, the blue colour changes to pink (compare Ber., 1887, 20, 335 ; 1893, 26, 2184). Unlike ethyl monoaminogallate, it cannot be precipitated from its aqueous solution by hydrochloric acid. It melts with decom= position at 197°. After drying in a vacuum, it was analysed. 0-1318 gave 0-1738 C02 and 0-0570 H20. C = 35-9 ; 11 = 4*8. 0-1330 „ 0-1746 C02 „ 0-0538 H20. C = 35 7 ; H = 4-5. 0-2129 „ 19-6 c.c. moist nitrogen at 23° and 764 mm. N= 10*4. 01588 „ by Carius’method, 0 1520 AgCl. 01 = 23-7. C9H1205N2,2HC1 requires 0 = 35-9; H = 4*6; N = 9*3; Cl = 23-6 per cent. In order to ascertain the action of nitrous acid on this diamino-ester, 66 grams of the substance were mixed with an excess of dilute hydro¬ chloric acid. The resulting dark coloured solution was cooled with water and a dilute solution of sodium nitrite gradually added, which caused considerable effervescence and the evolution of some nitrous fumes. This liquid was extracted with ether, but on distillation the latter left only a very slight residue. The remaining liquid was heated on a water-bath, when there was considerable effervescence, and, after this had ceased, a small portion of the liquid, when boiled with potassium hydroxide, evolved ammonia. The remainder was extracted with chloroform, then made alkaline with sodium carbonate and again extracted with chloroform, but in neither case was any definite product obtained. The Wellcome Chemical Research Laboratories.