The synthesis of glyoxaline derivaties allied to pilocarpine / by Frank Lee Pyman.
- Pyman, Frank Lee.
- Date:
- [between 1910 and 1919?]
Licence: In copyright
Credit: The synthesis of glyoxaline derivaties allied to pilocarpine / by Frank Lee Pyman. Source: Wellcome Collection.
11/16 page 540
![trated hydrochloric acid. The liquor was then evaporated to dryness under diminished pressure, digested with 20 c.c. of absolute alcohol, and filtered from ammonium chloride (O'8 gram). The alcohol was then removed, and the residue dissolved in 1 litre of boiling water, agitated with the silver carbonate from 10 grams of silver nitrate, filtered from the silver chloride, treated with hydrogen sulphide, and again filtered. The solution was then evaporated to dryness under diminished pressure, when 8'0 grams of a nearly colourless varnish remained. This was dissolved in about 20 c.c. of absolute alcohol, and kept, when 1’6 grams of a-4(or 5)-glyoxaline- rnethyl-$-etkylsuccinic acid melting at 220—225° separated. The mother liquor gave no more crystalline matter; it was then again boiled for an hour with concentrated hydrochloric acid, and the above process for the isolation of the free crystalline acid repeated, but still gave no more crystals. The residue was then esterified by means of absolute alcoholic hydrogen chloride, and the esters obtained converted into the acid oxalates and crystallised from water, when a mixture of crystalline oxalates was obtained. By fractional crystallisation from water a small quantity of a salt was separated, which melted at 133—135° (corr.), gave on analysis figures (0 = 51*7; H = 6'7) agreeing for the ester oxalate, and when mixed with the pure ester oxalate [m. p. 137—139° (corr.)] melted at 135—138° (corr.). The oily ethyl a-cyano-a-4(or 5)-glyoxalinemethyl-/3-ethylsuccinate (A, p. 539), amounting to 15 grams, was then hydrolysed, and treated in the same way as the crystalline ester, when a very similar result was obtained. The ammonium chloride separated amounted to O'9 gram, the crude acids to 10'1 grams, the crystalline acid to 1*55 grams, m. p. 220—225°, and on esterifying the residue a similar mixture resulted. The crystalline and oily cyano-esters therefore appear to yield on hydrolysis the same mixture of acids in the same proportion. a-4(or 5)-Glyoxalinemethyl-fi-ethylsuccinic acid, prepared from either the crystalline or oily cyano-ester and crystallised from water, melts and decomposes at 236° (corr.), and a mixture of the acids from the two sources at the same temperature. It crystallises in crusts formed of clusters of glistening needles. It is anhydrous, and is sparingly soluble in cold, although readily so in hot, water, and very sparingly soluble in alcohol: 0'0921 gave 0*1783 C02 and 0*0513 H20. C = 52*8; H = 6*2. C10H14O4N2 requires C = 53'0; H = 6'3 per cent.](https://iiif.wellcomecollection.org/image/b30622244_0011.jp2/full/800%2C/0/default.jpg)
