08-19-02 12:17
No 346640
I have a reference for the reaction of phenylacetic acid and ammonium acetate (Kao and Ma, J. Chem. Soc., 1930, 2788; 1931, 443.) and for the reaction of phenylacetic acid and urea (Das-Gupta, J. Ind. Chem. Soc., 10, 117 (1933).) Both form phenylacetamide. Unfortunately I do not currently have access to either journal. If anyone is able could you please look up these references and advise on the reaction conditions and yield
(Chief Bee)
09-02-02 10:13
No 351710
I think there is a procedure in ../rhodium /vogel3.
(Moderator)
09-05-02 21:40
No 353107
The experimental from the article by Das-Gupta
Reactions of Acids and Anhydrides with Urea.
In most of these reactions, the mixtures are heated at 150-170° and then cooled and washed with small amounts of water. The residue is washed with dilute ammonia or alkali. The aliphatic imides are either extracted with some solvents or recovered by distillation. Aromatic imides are obtained in practically pure state by simply washing with dilute ammonia or alkali. Excess of urea is used in most of the cases, while with lesser amounts some of the acids or anhydrides remain unreacted. Relative proportions of the ammonium salts and amides formed also depend to some extent on the amount of urea used and also on the temperature and duration of heating.
Decomposition of phenylurea in acetic acid solution.-A mixture of phenylurea (1 g.) and glacial acetic acid (5-6 cc) was gently reluxed for about 1 hour. It was next cooled and diluted with water, when a crystalline precipitate of diphenylurea separated out. On recrystallisation from alcohol, it melted at 236°.
Reactions of urea in various solvents.-Reactions of urea in glycerol were carried at 120°, in acetic acid at 117°, in water at 95-100° (except where stated), usually for 2 hours and in alcohol at 82° for 5 hours. Yields in 50% alcoholic solution were always greater than in 95% alcohol but these were small in both cases. The products were obtained by distilling off the alcohol under reduced pressure. From glycerol and acetic acid solutions, these were separated by diluting with water and proceeding in the usual way.