- Derivatives of 2, 3, 6-trifluorophenols and a process for their preparation
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The present invention relates to compounds of the formula (1) STR1 where R is H, a straight-chain or branched alkyl radical with 1 to 6 carbons, a fluorinated straight-chain or branched alkyl radical with 1 to 6 carbons, a benzyl radical, or a benzyl radical substituted by an alkyl group or alkoxy group with 1 to 4 carbons each, or by halogen, X is H, Cl, Br or I, and X is different from R, and a process for their preparation.
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- Mechanisms for Reactions of Halogenated Compounds. Part 3. Variation in Activating Influence of Halogen Substituents in Nucleophilic Aromatic Substitution
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Rate constants are reported for reactions of polyhalogeno-pyridines and -benzenes with sodium methoxide in methanol.Relative activating effects of individual fluorine and chlorine atoms at positions ortho, meta, and para to the reaction site are determined and compared with orders determined from reactions involving ammonia in aqueous dioxan.The results are remarkably similar.Additional support is provided for earlier explanations of the activating effects of ortho-fluorine and -chlorine.Activation parameters, determined for reactions of polyhalogenepyridines with ammonia in aqueous dioxan, clearly demonstrate that differences in reactivity along the series arise mainly from changes in activation energy.
- Chambers, Richard D.,Close, Deborah
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p. 778 - 780
(2007/10/02)
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