ON ISOMERIC NAPHTHALENE DERIVATIVES. 



177 



Br Br 



Br 

 Flessa's penta-bromo- 

 p-iiaphthol, in.p. 243" ; 

 aceliite, m.p. 2U9^. 



Br 

 Br,/\/\0H 



Br O 



Br^j^JcrC?) 



Br 



Tetra-bromo quinone, 

 nvp. 214°. 



Br^/I^Br(?) 



Br 



New penta-bromo-j3-naphthol, 



m.p. 25^^ ; aceluir; m.p. 201- 



202°, sleuder needles. 



Br 

 Br/\/\0 



Br 

 Penta-bromo-/3-iiaphtlia 

 quiuono, m.p. 237°. 



Br 



Br^ .CO,H 



Br 

 Tri-bromophthalio 

 acid, m.p. 210° ; anhii- 

 (IrlUe, m.p. 178°. ' 



Br 

 Brf^CO.H 



— > 



Bri^^CO.H 

 Br 



Tetr.vbromoplithalio 

 acid, m.p. 2G5-2Gli° ; 

 an/ii/tlriJe, m.p. 2G9°. 



The ricature of the two penta-bromo-/3-naphthols obtained a.s ultimate 

 products on brominating 1:3: 6-tri-bromo-iS-naphthol is established by 

 the fact that they are both formed on brominating 1:3:4: 6-tetra- 

 bromo-2-naphthol (m.p. 172"), and the following considerations : — 



Br 



Tri-bromo-/3-naphthol, 

 m.p. 155°. 



Br 



■ r.rMjBr^ 



Bi- 



Tetra-bromo- j3- 

 naplithul, m.p. 172° 



Br 

 Br'^V^OH 



Br^^;Br 



^ Br 



^ renta-bromo- 

 (3-iiapUthol, m.p. 

 205°-206° ; acelale, 

 m.p. 203°. 

 Br 



Br Br 



Er/Y^O 



Br 

 Tetra-bromo- 

 /3-napUtha quiuoue, 

 m.p. 209°. 



Br 

 Br Br 



Br 

 Br 



/\ 



CO,H 

 CO„H 



Peuta-bromo-/3-iiaphthol, Penta-bromo 



m.p. 225° ; ficetale, 

 m.p. 215°. 



Di-bromo- 



phthalic acid 



(Brilok '). 



Br 



BrI CO,H 



Br 

 Tri-bromo- 



quiuoiie, m.p. 212-. plitlialic acid, 

 m.p. 210°. 



Flessa has previously - described the penta-bromo-naphthol melting 

 at 243° as melting at 237°, and the derived tetra-bromo-/S-naphtha 

 quinone (m.p. 214°) as melting at 164° ; but his quinone separated from 

 all solvents only in ' crystalline granules,' whereas the substance meltint' 

 at 214° forms magnificent flattened needles. Flessa's tri-bromophthalic 

 acid melted at 191° and tlie anhydride at 157° ; whereas the acid from the 

 quinone melting at 214° melts at 210°, and its anhydride at 178°. The 

 structure of this acid, which has not hitherto been established, follows 

 from the results represented in the above schemes ; it is 3 : 4 : 6 tri- 

 bromophthalic acid. 



It is of great interest that whereas two of the penta-bromo- 

 yS-naphthols give tetra-bromo-p-naptha quinones in the normal manner, 

 when the bromo-nitro-keto compounds are decomposed by boilin"' with 

 glacial acetic acid, two, viz. — 



Br 



OH 



and 



BrLJl^ jBr 



Br Br 



' Bruck, Ber., 1901. 2741 ; 

 monomethyl .salt, m.p. 81°. 



OH 



Br(?) 



1902, 



3cid, m.p. 211-213°; anhydride, m.p. 212-213°- 



? Ber., 17, 1479. 



N 



