4-beta-Methylaminoethylglyoxaline / by Robert George Fargher and Frank Lee Pyman.
- Fargher, Robert George.
- Date:
- 1921.]
Licence: Public Domain Mark
Credit: 4-beta-Methylaminoethylglyoxaline / by Robert George Fargher and Frank Lee Pyman. Source: Wellcome Collection.
4/8 page 737
![When less concentrated solutions of methylamine were em¬ ployed, the yield of methylhistidine was diminished; thus, when a 29 per cent, solution of methylamine was used, the yield of methyl¬ histidine amounted to only 20 per cent, of the theoretical. a - M ethylamino-(i-glyoxalin e - 4 - propionic acid dipicrate crystallises from water in well-defined, prismatic needles containing 3 mole¬ cules of water of crystal]isation, two of which are lost at 60° in a vacuum, and the third slowly at 90° in a vacuum. The air-dried picrate sinters at about 70°, owing to loss of water of crystallisation, and melts definitely at 132° (eorr.). It dissolves readily in boiling water but only sparingly in cold (Found : in air-dried material, loss at 60° in a vacuum = 5-4. C7H1102N3,2C6n307N3,3H20 re¬ quires loss of 2H20, 5*3 per cent. Found : in dried material, C = 35*3; IT = 3*3; N — 19-3 ; further loss at 90° in a vacuum = 2- 8. C7Hn02N3,2C6H307N3,H20 requires C = 35-3; IT = 3-0; N = 19-5; H20 — 2-6 per cent.). Five grams of air-dried picrate gave 3*32 grams of picric acid, 3- 36 grams being required. a - M ethylami no- p-glyoxalin e - 4 - pro pi o nic acid sesquipicrate, which closely resembles the dipicrate, crystallises from water in large, glistening, rhombic prisms, which melt at 193° (corr.) and appear to contain 7 molecules of water of crystallisation, of which six are lost at 60° in a vacuum, whilst the last is retained even on further heating at 110° (Found : in air-dried material, loss at 60° in a vacuum = 9-6, 9*4; C = 33T ; H = 3-7. 2C7Hh02N3,3C6H307N3,7H20 requires loss of 6H20 = 9-4; C = 33-35; H = 3-9 per cent. Found : in dried material, C = 36-8; H = 3-2; N = 20-0. 2C7H1102N3,3C6H307N3,H20 requires C = 36-8; II = 3-2; N = 20-1 per cent.). a.-Methylamino-$-glyoxaline-4:-propionic acid monopicrate was ob¬ tained by treating the solution of the base with a molecular pro¬ portion of picric acid. It is sparingly soluble in water, from which it separates in minute, flattened prisms, which melt and effervesce at 118° (corr.) and contain 3 molecules of water of crystallisation, which are not lost on heating at 60° in a vacuum (Found : C = 34-7 ; H = 4-3. C7H1102N3,C6H307N3,3H20 requires C = 34-5; II = 4-45 per cent.). <z-Methylamino-fi-glyoxaline-4:-propionic acid dihydrochloride was prepared from the picrate in the usual manner and crystallised from dilute hydrochloric acid in large, diamond-shaped, colourless plates, which softened at about 127° and melted at 134° (corr.). It dissolves very readily in water, but only sparingly in alcohol. The air-dried salt contains one molecule of water of crystallisation,](https://iiif.wellcomecollection.org/image/b30622992_0004.jp2/full/800%2C/0/default.jpg)
