JOURNAL 



OF THE 



EUSHA MITCHELL SCIENTIFIC SOCIETY 



VOLUME XXIX APRIL. 1914 No. 4 



THE KEDUCTI0:N^ of InTAPHTAZARINE 



BY ALVIX S. WIIEELEK AND CHAS. S. VEXABLE 



The reduction, of naphtazarine was first carried omt by Zincke 

 and Schmidt (Ann., 286,27 (1910)). The more descriptive 

 name of this compound is, 1, 2-dihydroxy-5, 8-naphthoqiiinone, 

 formerly called 5, 6-dihydroxy-l,4-napthoqiiinone. The au- 

 thors mentioned employed stannous chloride and hydrochloric 

 acid, stating that the reaction, did not go to completion if zinc 

 dust was used. The reddish brown quinone is converted into 

 the dull yellow tetrahydroxynaphthalene, designated by them 

 as 1,4,5, 6-tetraoxyuaphthalene, now more properly described as 

 the 1, 2, 5, S-tetrahydroxynapthalene. This compound is a pe- 

 culiarly interesting on.e on account of the ready change which 

 it undergoes in solutions. In the solid state it consists of yel- 

 low needles which turn red as they melt at 154°. All solutions 

 in organic solvents turn red on standing, and a product more or 

 less red is recovered therefrom. When pure this substance also 

 melts at 154°. According to Zincke and Schmidt it has the 

 same composition as the yellow reduction product. In view of 

 the ready oxidation of the yellow tetrahydroxnaphthalene to the 

 reddish brown naptazarine, the authors came to the conclusion 

 that the red product melting at 154° was in reality the yellow 

 compound mixed with a small amount of oxidation products. 

 They obtained the same acetyl derivative from the yellow and 

 the red compounds. We are unable to concur in. this view, 

 knowing what a marked effect in lowering the melting point 

 only slight quantities of impurities have. We propose another 

 explanation which lies in the theory that we have here a case of 

 desmotropy in which a labile hydrogen is causing a keto-enol 

 isomerism. 



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