The synthesis of histidine / by Frank Lee Pyman.

  • Pyman, Frank Lee.
Date:
[between 1900 and 1909?]
Catalogue details

Licence: In copyright

Credit: The synthesis of histidine / by Frank Lee Pyman. Source: Wellcome Collection.

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    of ethyl 4(or 5)-glyoxalinemethylmalonate hydrogen oxalate, that is, 49 per cent, of the theoretical. Ethyl 4(or o)-glyoxalinemethylmalonate hydrogen oxalate crys¬ tallises from water in large, hard, clear, nearly rectangular, oblong plates, which melt at 155—158° (corr.). It is anhydrous, sparingly soluble in cold, but readily so in hot, water: 0*1488 gave 0*2564 C02 and 0*0727 H20. 0 = 47*0; H = 5*5. 0*1413 „ 106 c.c. N2 at 19° and 778 mm. N = 9*0. CnH1604N2,C2H204 requires 0 = 47*2; H = 5*5; N = 8*5 per cent. The base was regenerated from the oxalate by means of sodium carbonate and ether; after distillation of the solvent, it remained as a yellow oil, which became very viscid when cold, but readily poured when warm. It showed no signs of crystallisation after long keeping. It is sparingly soluble in water, but readily so in alcohol or ether. The hydrochloride occurs as a deliquescent mass of needles, melt¬ ing indefinitely at 50—70°, and readily soluble in water, alcohol, acetone, or ethyl acetate. The hydriodide is a crystalline salt of similar properties. 4(or 5)-Glyoxalinemethylmalonic Acid, NH-CH ^h_n>c-ch2-cu(c°2h)2. Ethyl 4(or 5)-glyoxalinemethylmalonate was boiled with an excess of baryta water for several hours; a stream of carbon dioxide was then led through the liquid, and the barium carbonate removed by filtration. The clear filtrate, containing the barium salts of 4(or 5)-glyoxalinemethylmalonic acid and /3-glyoxaiine-4(or 5)-pro pionic acid, was then made up to a known volume, and the barium in an aliquot portion determined. The liquor was then treated with a quantity of oxalic acid exactly sufficient to remove the barium, filtered from barium oxalate, and concentrated to low bulk, when 4(or 5)-glyoxalinemethylmalonic acid crystallised out on cooling; the mother liquor contained /3-glyoxaline- 4(or 5)-propionic acid. 4(or b)-Glyoxalinemethylmalonic acid crystallises from water in beautiful, clear, hexagonal plates. It is easily soluble in hot water, but sparingly so in cold water or alcohol: 0*1512 gave 0*2530 C02 and 0*0596 H20. 0 = 45*6; H = 4*4. 07H8O4N2 requires 0 = 45*6; 11 = 4*4 per cent. When heated, this malonic acid melts and effervesces at 180° (corr.), losing carbon dioxide; it resolidifies while still hot, and does not then melt until 207° (corr.), /Tglyoxaline-4(or 5)-propionic acid,