| 摘要 |
Oxidation of secondary amines with hydrogen peroxide and sodium tungstate is reported to give good yields of nitrones. However, when using dimethylamine in this manner, a considerable amount of N,N-dimethylformamide was produced as a co-product. To more selctively produce N-methylnitrone from dimethylamine, a two-step process is used which comprises (a) mixing together dimethylamine and a peroxidic compound, and subjecting the resultant mixture to reaction conditions effective to form a reaction mixture in which N,Ndimethylhydroxylamine has been formed; and (b) mixing together (i) reaction mixture from (a), (ii) a peroxidic compound, and (iii) a transition metalcontaining oxidation catalyst, and subjecting the resultant mixture to reaction conditions effective to form a reaction mixture in which Nmethylnitrone has been formed. Highest yields of N-methylnitrone are achieved by conducting step (b) at a pH in the range of 7 to 12, and at a temperature in the range of -10 to 100 ~C.
|
