298 



REPORT 1900. 



former contains two, of its bromine atoms in the hydroxy lated ring — 

 -which is proved to be the case by their behaviour on oxidation, the tribro- 

 monaphthol melting at 159° being convertible into dibromo-, and that 

 melting at 155° into bromo-phthalic acid — so that in the one case the non- 

 hydroxylated ring, and in the other the hydroxylated ring, is attacked. 



Unexpected difficulties have been encountered in attempting to deter- 

 mine the position of the second bromine atom in the hydroxylated nucleus 

 of the tribromonaphthol melting at 155°. This compound affords a 

 dibromoquinone isomeric with that produced on decomposing the dibromo- 

 nitroketo-compound derived from dibromonaphthol. Both these dibromo- 

 quinones are converted into 1:3:4 bromophthalic acid on oxidation. 

 Consequently the one contains a bromine atom in position 3, and the other 

 a bromine atom in position 4. When subjected to the action of aniline, 

 howevei', both yield the same two anilides. 



O 







and 



Br 



NH.Ph 



N^ 



NH.ph 



Nll.Ph 



Nor have results yet been obtained by means of alkalies which afford a 

 solution of the problem. 



The dibromoquinone obtained from the bromonaphthol melting at 155° 

 is remarkably sensitive to oxidation, being slowly converted into the 

 dibromohydroxy- quinone when kept ; a result which appears to favour 







the view that bromine is present in the tribromonaphthol in position 3. 

 The dibromoquinone in question may be recrystallised from ethylic acetate, 

 but if left too long in contact with the solvent it is converted into an 

 infusible condensation product. This quinone is therefore a compound 

 which it will be desirable to study in detail. 



The tribromonaphthol melting at 155° is acted on with difficulty by 

 bromine, remaining for the most part unchanged when its solution in 

 acetic acid is digested with bromine during thirty to forty hours at 100° 

 to 120°, only a small portion being converted into the tetrabromonaphthol 

 melting at 172°, described by Armstrong and Rossiter. The tribromo- 

 naphthol melting at 159°, under similar conditions, is without difficulty 

 converted into a tetrabromonaphthol melting at 1 84°, which is convertible 

 into a tribromoquinone isomeric with that obtainable from the isomeric 

 tetrabromonaphthol. A third tetrabromonaphthol has been obtained in 

 small quantity together with that melting at 184° by acting directly on 

 betanaphthol with dry bromine. It is distinguished by yielding a tetra- 

 bromonaphthaquinone. 



Both tribromonaphthols are easily reduced at 100° by a saturated 



