LETTERS TO THE EDITOR
THE
MECHANISM
COMPOUNDS
WITH
OF
REACTIONS
OF
NUCLEOPHILIC
BROMOQUINONE
AGENTS
V. V. Ershov, A. A. Volod'kin, A. L. Bulaehenko, D. Kh. Rasuleva, and V. I. Volod'kina
UDC 541.124+547.567
We have found 2,4,6- t r i - t e r t - b u t y l p h e n o x y l (II) as the p r i m a r y product of the r e a c t i o n of 4 - b r o m o - 2 , 4 , 6 t r i - t e r t - b u t y l e y e l o h e x a d i e n - 2 , 5 - o n e (I) with a methanolic solution of p o t a s s i u m (or sodium) methylate, an aqueous--alcoholic alkali solution, and a m i n e s . The EPR s p e c t r u m of (II) was obtained in the c o u r s e of these r e a c t i o n s d i r e c t l y in the r e s o n a t o r of an E P R - 2 i n s t r u m e n t (triplet with a split of 1 . 8 0 e ) . The final reaction products (after d i s a p p e a r a n c e of the EPR signal of the phenoxyl r a d i c a l (II), f o r example in the r e a c t i o n of bromoquinone (I) with p o t a s s i u m methylate in methanolic solution, w e r e the methyl e t h e r of the c o r r e s p o n d i n g quinol (iII) [1] and 2 , 4 , 6 - t r i - t e r t - butylphenol (IV). The quinolic peroxide (V) was also f o r m e d when this r e a c t i o n was c a r r i e d out in the p r e s e n c e of a t m o s p h e r i c oxygen.
o
o
R = C { C H J a, * Br
L
Ill
o
""OCH~ ~IJl}
*
CHa()
.
R
O
~11~
6
OH
R {l])
R
R
tlV~
02
It follows that in the r e a c t i o n of bromoquinone (I) with typical nucleophilic r e a g e n t s (CH30-) a single e l e c t r o n t r a n s f e r takes place f r o m the molecule of the nucleophile to the bromoquinone compound. The f o r mation of the m e t h y l e t h e r of quinol (III) can be explained by the r e c o m b i n a t i o n of r a d i c a l (ID with CH30", and the f o r m a t i o n of the quinolic peroxide by the recombination with oxygen [2]; the phenol (IV) is f o r m e d as a r e s u l t of dehydrogenation of methanol with the phenoxyl r a d i c a l (II) [3]. LITERATURE 1. 2. 3.
CITED
E. MiiUer, K. Ley and W. Kiedaisch, Chem. B e r . , 87, 1605 (1954). E. MUller and K. Ley, Z. N a t u r f o r s c h . 8B, 694 (1953}. E. Miiller, K. Ley, and G. Schlechte, Angew. Chemie, 69, 704 (1957).
...... Institute of Chemical P h y s i c s , Academy of Sciences, USSR. T r a n s l a t e d f r o m I z v e s t i y a Akademii Nauk SSSR, Seriya Khimicheskaya, p. 972, April, 1969. Original article submitted D e c e m b e r 24, 1968.
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