Determination of radicles in carbon compounds / by Dr. H. Meyer. Authorized translation by J. Bishop Tingle.

  • Meyer, Hans (Hans Johannes Leopold), 1871-
Date:
1903
Catalogue details

Licence: In copyright

Credit: Determination of radicles in carbon compounds / by Dr. H. Meyer. Authorized translation by J. Bishop Tingle. Source: Wellcome Collection.

    131/200
    The method employed for the hydrolysis of very stablc amides 1 is best illustrated by its application to the prep- aration of triphenylacetic acid.~ The finely divided amide (0.2 gram) is gently warmed with concentrated sulphuric acid (1 gram) and the clear solution cooled in ice, sodium nitrite (0.2 gram), dissolved in water (1 gram), cooled to o°, is added very slowly by means of a capillary tube; when the addition is complete the test- tube containing the mixture is placed in a beaker of water and gradually heated. The evolution of nitro- gen commences at 6o°-70°, and is completed at 8o°-go°; finally the tube is heated in boiling water for 3-4 minutes, but not longer. When cool, ice is added to the liquid, the precipitated solid collected, and puri- fied by solution in dilute sodium hydroxide and precipi- tation with sulphuric acid. It is highly desirable to use the exact theoretical quantity of sodium nitrite dis- solved in the smallest possible volume of water.3 The amide may also be dissolved in sulphuric acid (20-30 per Cent), and to the boiling liquid sodium nitrite solu- tion (5-10 per cent) added; (1.5-2 mol. for each CO.NH2 group). The boiling is continued until gas evolution ceases.4 y-Hydroxyvaleric amide is completely hydrolysed only if it is boiled down to dryness with dilute hydro- chloric acid, or heated in a reflux apparatus for f hour in a current of air.5 Stereo-chemical influences are efifective in 1 Bouveault, Bull. [3], 9, 370. 2G. Heyl and V. Meyer, B. 28, 2783. 3 Sudborough, Jour. Chem. Soc. 67, 604. 4 L. Gattermann, B. 32 (1899), 1118. 6 E. L. Neugebauer, Ann. 227 (1SS5), 105.