Drushel and Knapjp — Ghjcocoll and Diethyl Carbonate. 509 



Art. XXXIX. — On the Preparation of Glyeocoll and Diethyl 

 Carbonate ; by W. A. Drushel and D. R. Knapp. 



[Contributions from the Kent Chemical Laboratory of Yale Univ. — cclxxiv.] 



The preparation of glyeocoll by the interaction of ammonia 

 and chloracetic acid is attended by by-reactions which make it 

 impossible to obtain a quantitative yield of the amino acid. In 

 1858 Perkin and Duppa* obtained a small yield of glyeocoll 

 by the action of ammonia upon bromacetic acid at the boiling 

 temperature; later Cahours,f repeating the experiment with 

 chloracetic acid, got a yield of 10 per cent to 15 per cent. 

 Mauthner and Suida^: improved the yield by working with 

 ammonia and chloracetic acid in the cold, and more recently 

 Kraut was able to get a yield of 50 per cent to 55 per cent by 

 cooling the reaction mixture to 10°. The very marked improve- 

 ment in yield obtained by Kraut suggested the possibility of 

 even a better yield by working at 0° and keeping the reaction 

 mixture saturated with ammonia until all of the chlorine was 

 fixed as ammonium chloride. 



In this investigation 700 cm3 to 800 cm3 of ammonia water 

 were cooled to 0° in an ice bath, and saturated at this tempera- 

 ture with gaseous ammonia. One hundred grams of chlorace- 

 tic acid were dissolved in the least possible amount of water 

 and slowly run into the ice cold saturated solution of ammonium 

 hydroxide, keeping the reaction mixture at 0° and saturated 

 by passing gaseous ammonia. In our earlier experiments the 

 mixture was kept at 0° for about fifteen hours and was then 

 allowed to stand at room temperature for several days. In the 

 later experiments the temperature was kept at 0° for more than 

 four days ; the reaction was found to go to completion at this 

 temperature in about five days. The velocity of the trans- 

 formation of the chloracetic acid was determined by pipetting 

 off 5 cm3 portions of the reaction mixture from time to time, 

 neutralizing the excess of ammonia with ice cold nitric acid 

 and titrating the ammonium chloride present with standard 

 silver nitrate, using potassium chromate as an indicator. A 

 good concordance in velocity constants was obtained by mak- 

 ing the calculation from the usual formula for second order 

 reactions. The mean of a series of five velocity constants is 

 - 000223. The glyeocoll was recovered from the reaction 

 mixture and purified by the copper hydroxide method ; the 

 use of copper carbonate instead of copper hydroxide suggested 



* Quart. Jour. Chem. Soc, xi, 22. 

 fCompt. rend., xlvi, 1044; cvii, 147. 

 JMonatsh., xi, 374. 

 § Ann. Chem. Pharm., eclxvi, 299. 



