The action of aniline on d-glutamic acid / by W.H. Gray.

  • Gray, William Herbert.
Date:
[1928.]
Catalogue details

Licence: Public Domain Mark

Credit: The action of aniline on d-glutamic acid / by W.H. Gray. Source: Wellcome Collection.

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    instance the properties of a 2-pyrrolidone-5-carboxylic acid. Attempts to reduce the substance so prepared were made, in order to be certain that it was not actually the enolic form, possibly indis¬ tinguishable from pyrrolidonecarboxylic acid by the other tests applied. In these attempts, hydrogen under a pressure of two atmospheres was used, and either Willstatter’s platinum-black as modified by Feulgen (Ber., 1921, 54, 360), the very active platinum oxide-ferrous salt catalyst of Adams (J. Amer. Chem. Soc., 1922, 44,. 1397), or palladinised barium sulphate, the activity of these being verified in every case by control reduction of quinine or salicyl- aldehyde, but in no case was hydrogen absorbed. This is additional evidence of the identity of the diphenylamine-treated product with 2-pyrrolidone-5-carboxylic acid, in which, as in other 2-pyrrolidone derivatives, the carbonyl group is resistant to reduction (compare Tafel and Stern, Ber., 1900, 33, 2226; McCay and Schmidt, J. Amer. Chem. Soc., 1926, 48, 1933; Ramart-Lucas and Fasal, Compt. rend.,. 1927, 184, 1253; and Darapsky, J. pr. Chem., 1927, 116, 129). The previous work of Hugounenc, Florence, and Couture {Bull. Soc. Chim. biol., 1924, 6, 672) appears to have been overlooked. These authors heated d-glutamic acid with aniline and obtained a product having practically the same melting point as that found by Abderhalden and Schwab. They correctly called this an anilide but, incorrectly, the anilide of glutamic acid. ExPEEI MENTAL. l-2-Pyrrolidone-5-carboxyanilide (II).—A mixture of d-glutamie acid (43-5 g.) and aniline (217 c.c.) was heated under reflux at 205—210° for J hour, cooled, and filtered from a small undissolved residue. Ether (130 c.c.) was then added, and the crystalline solid which separated was washed with ether and dried (20*8 g., m. p. 187°). The filtrate was concentrated and treated with ether, giving a further 8*8 g. After one recrystallisation from methyl alcohol the anilide was obtained pure, m. p. 191°, -f- 17-9° in 80% alcohol (c = 4*8). The foregoing procedure is that of Abderhalden and Schwab; a better yield and a cleaner product are obtained by heating tho mixture at 150° instead of 210° and treating the product with acetone in place of ether. Water or ethyl alcohol is equally effective for recrystallisation; the anilide separates from the latter in well- formed, flat tablets with pointed ends, exhibiting a considerable twinning tendency. It is readily soluble in cold glacial acetic acid^ P-chloroethyl alcohol, or concentrated hydrochloric acid, moderately easily soluble in methyl and ethyl alcohol, sparingly in cold water but more readily on heating (1 in 7*4), and almost insoluble in benzene (Found : C, 64*7; H, 6*0; N, 13-5. CiiIIjoGoNg requires