- Reactions of 4-dialkylamino-5-methoxy-1,2-benzoquinones in acidic media: Selective C-alkylation or N-dealkylation
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4-(N-methyl-alkylamino)-5-methoxy-1,2-benzoquinones 3, for which N-alkyl group R1 can give rise to a stabilized carbonium ion, undergo selective acid-catalyzed rearrangements to 3-alkylated-1,2-benzoquinones 4. Aziridino- quinone 10c gives rise to the heterobicyclic 1,2-benzoquinone 11. When R1 does not contain groups capable of stabilizing a positive charge, efficient and selective N-dealkylations occur. The mechanisms of these reactions are discussed.
- Viallon, Loik,Reinaud, Olivia,Capdevielle, Patrice,Maumy, Michel
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p. 7841 - 7854
(2007/10/03)
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- Synthesis of 5-alkoxy-4-alkylamino-1,2-benzoquinones
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A simple and efficient method is described for a general synthesis of 4-dialkylamino-5-methoxy-1,2-benzoquinones 3 which involves, in polar solvents, a regioselective (>95%) nucleophilic monosubstitution by a wide range of secondary aliphatic amines on an easily prepared 1,2-quinone 1. Regioselectivity is not observed in the reaction of primary amines with 1, but a further reaction with an alcohol in basic medium allows valorization of the undesirable product.
- Viallon,Reinaud,Capdevielle,Maumy
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p. 1534 - 1538
(2007/10/02)
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- Synthesis of new 4-alkylamino-5-methoxy-2H-pyran-2-ones
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4-alkylamino-5-methoxy-1,2-benzoquinones 2a, b are selectively oxidized by magnesium monoperoxyphtalate (MMPP) into new 4-alkylamino-5-methoxy-2H-pyran-2-ones 3a, b. The acid-catalyzed migration of a benzhydryl group (3a → 3b) as well as its quantitative
- Viallon, Loik
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p. 6669 - 6672
(2007/10/02)
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