less. The copper salt is bluish green and the iron salt is yellowish 

 brown in color. Various salts of inosite phosphoric acid which we 

 have prepared and analyzed will be described in the experimental part. 



SYNTHETIC ESTERS OF INOSITE AND PHOSPHORIC ACID 



Several unsuccessful attempts have been made to synthesize phy- 

 tic acid or the inosite phosphoric acid. Neuberg and Kretschmer 

 (1911) report obtaining a polyphosphoric acid ester of inosite by 

 their method of preparing phosphoric acid esters of carbohydrates 

 and glycerin ; that is, by the action of phosphorus oxychloride. They 

 could not obtain any pure product, however, as it was found impos- 

 sible to separate the new compound from inorganic phosphates. 



Contardi (1910) claims to have succeeded in preparing inosite 

 hexaphosphoric acid by heating inosite with an excess of phosphoric 

 acid at a temperature of 160 to 165° in an atmosphere of carbon dioxide. 

 The product was purified as the barium salt and the free ester whicn 

 was finally obtained he described as identical with "phytic acid" which 

 was prepared from rice bran. The same author claims to have pre- 

 pared polyphosphoric acid esters of mannite quercite and glucose by 

 the same methods. 



Carre (1911) was unable to substantiate the results of Contardi 

 and stated that the reaction mixtures in question consisted only of 

 free phophoric acid and the poly-hydric alcohols, together with some 

 decomposition products. 



Contardi (1912) answered this criticism by repeating his work and 

 claimed to show that his original conclusions were correct. 



The results of our experiments showed that inosite and phosphoric 

 acid react when heated to 140 to 160° in vacuum and that water is 

 given off. The reaction product after purifying as a barium salt and 

 removing inorganic phosphoric acid gave results on analysis corre- 

 spending to inosite tetraphosphoric acid, C H 6 (OH) 2 (PO4H.Jp 

 (Anderson 1912 (1) ). It was also found that inosite and pyrophos- 

 phoric acid react at a temperature of about 200° with the production 

 of esters (Anderson 1912 (2) ). 



Jegorow (1914 (1) ) has more recently reported some experiments 

 along the same line. Inosite and phosphoric acid were heated in a 

 flask in an atmosphere of hydrogen or nitrogen. He noted that the 

 final reaction product contained 22.6 per cent of organic phosphorus. 

 There is no doubt but that esters of phosphoric acid are produced 

 when inosite and phosphoric acid are heated together, but we do not 

 believe that inosite hexaphosphoric acid or phytic acid can ever be 

 prepared in this way. Contardi, for the reasons mentioned below, 

 must have been in error when he claimed to have synthesized the sub- 

 stance by this method. Numerous experiments have shown that phytic 



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