- A homologous series of O- and N-functionalized 2,2-difluoro-1,3-benzodioxoles: An exercise in organometallic methodology
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The conversion of 2,2-difluoro-1,3-benzodioxole, an exceptionally acidic arene, via a 4-lithiated intermediate into more than three dozen new derivatives was conceived as a case study. The lithiated species was trapped by C0-electrophiles (4-toluenesulfonyl azide, fluorodimethoxyborane, iodine), C1-electrophiles (carbon dioxide, N,N-dimethylformamide, formaldehyde, dimethyl sulfate), C2-electrophiles (oxalic acid diesters, oxirane), C3-electrophiles (oxetane), and higher alkyl iodides. The resulting carboxylic acid 1a may be treated with organolithium compounds to afford ketones (e.g. 10) and the aldehyde 9 can be condensed with nitromethane or acetic anhydride under basic conditions. If not oxidized with chromium trioxide to the corresponding carboxylic acids, the alcohols 2b, 2c, and 2d can be transformed into the corresponding bromides (12) or sulfonates (13). Their condensation with nitrogen-containing C0-nucleophiles (hydroxylamine, sodium azide, potassium phthalimide), C1-nucleophiles (potassium cyanide), and C2-nucleophiles (aceto-nitrile) opens a convenient access to the amines 3. Other reactions gave, despite a proven track record in other areas, only moderate yields. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
- Schlosser, Manfred,Gorecka, Joanna,Castagnetti, Eva
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p. 452 - 462
(2007/10/03)
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- Herbicidal benzodioxoles and benzodioxanes
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Compounds of Formula I, and their N-oxides and agriculturally-suitable salts, are disclosed which are useful for controlling undesired vegetation STR1 wherein: STR2 T is O or S; W is a single bond, O, S or NR6 ; X is N or CH; Y is N or CH; Z is
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- Derivatives of 2,2-dihalogenobenzo[1,3]dioxoles substituted in the 4-position, processes for their preparation and their use
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New 2,2-dihalogeno-benzo[1,3]dioxoles substituted in the 4-position, of the general formula (I) STR1 in which R represents fluorine, chlorine, bromine or nitro and Hal represents chlorine or fluorine, and their use as starting substances for the synthesis of highly active compounds, for example in the field of plant protection and pharmaceuticals. The compounds of the formula (I) can be prepared by analogous processes, for example by chlorination from corresponding benzo[1,3]dioxoles substituted in the 4-position, and these substances according to the invention can be further reacted with hydrogen fluoride to give substances to which the invention likewise relates.
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- Process for the preparation of 3-substituted 4-cyano-pyrrole compounds
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A process for the preparation of 3-substituted 4-cyanopyrrole compounds of the formula (I) STR1 in which Ar has the meaning given in the description, by reaction in a 1st stage of bromides (II) with acrylonitrile in the presence of a solvent and a suitabl
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