- Synthesis of dihalopicoline N-oxides and their 4-nitro derivatives
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Three aminohalo-substituted α- and β-picolines, six dihalo-substituted α- and β-picolines, six dihalo-substituted α- and β-picoline N-oxides and six respective dihalo-4-nitropicoline N-oxides were synthesized in excellent yields. Some properties of the products were reported. 1997 Plenum Publishing Corporation.
- Ciurla,Puszko
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p. 1173 - 1177
(2007/10/03)
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- HALOGEN-SUBSTITUITED PYRIDINES. 3.* CYCLIZATION OF ADDUCTS OF α,α-DICHLOROPROPIONITRILE WITH ACRYLIC DERIVATIVES TO CHLOROPYRIDINES
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Reactions of α,α-dichloropropionitrile with acrylic derivatives in the presence of Cu2Cl2 gave a series of substituted 2,4-dichloro- and 2-chloro-5-oxoalkanonitriles.Their cyclization to chloropyridines has been studied.
- Shvekhgeimer, M.-G. A.,Kobrakov, K. I.,Sychev, S. S.,Promonenkov, V. K.
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p. 428 - 433
(2007/10/02)
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- 2,2,4,4-tetrasubstituted 4-formylbutyronitrile intermediates for the production of trisubstituted pyridines
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2,2,4,4-Tetrasubstituted-4-formylbutyronitriles are intermediates for the preparation of the known 2-chloro-3,5-dimethylpyridine and 2,5-dichloro-3-methylpyridine which in turn are suitable for the production of different compounds, in particular insecticides and herbicides.
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- CONVENIENT APPROACHES TO HETEROCYCLES VIA COPPER-CATALYSED ADDITIONS OF ORGANIC POLYHALIDES TO ACTIVATED OLEFINS
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An efficient method for the synthesis of 2,3-dichloro-5-substituted (Cl, CF3, alkyl) pyridines 29 starting from the 1:1 adducts of the copper-catalysed addition of chloral or the corresponding 2,2-dichloroaldehydes to acrylonitrile is presented.Proper choice of experimental conditions allows the preparation of 29 in one-pot process.Similarly, the CuCl-catalysed reaction of methyl itaconate with several trichloromethyl compounds R-CCl3 gives 6-R-substituted 2-pyrone derivatives 40 via dehalogenation and subsequent thermal ring closure of the primary 1:1-adducts. The new electrophilic 2-pyrone 40b undergoes-cycloaddition reactions with inverse electron demand with a number of olefins and acetylenes, allowing thereby regioselective transfer of a trifluoromethyl group from a simple Freon derivative (1,1,1-trichloro-2,2,2-trifluoroethane) into more complex organic molecules.Finally, the 1:1-adduct of trichloroacetylchloride with methyl acrylate allows a very covenient synthesis of novel N-substituted derivatives 66 of pyroglutamic acid as well as of proline.
- Martin, Pierre,Steiner, Eginhard,Streith, Jacques,Winkler, Tammo,Bellus, Daniel
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p. 4057 - 4078
(2007/10/02)
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- Process for the production of chloropyridines substituted by methyl, trichloromethyl or trifluoromethyl groups
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Chloropyridines of the formula STR1 wherein either R is chlorine and R' is methyl or trifluoromethyl, or R is methyl, trichloromethyl or trifluoromethyl and R' is chlorine, or R and R' are methyl, can be obtained by a novel, simple process by the addition of trichloroacetaldehyde to methacrylonitrile or α-trifluoromethacrylonitrile, 2,2-dichloropropionaldehyde, pentachloropropionaldehyde or 2,2-dichloro-3,3,3-trifluoropropionaldehyde to acrylonitrile, or 2,2-dichloropropionaldehyde to methacrylonitrile, in the presence of a catalyst, in particular copper powder or copper(I) chloride, and cyclizing the open-chain intermediate obtained. The chloropyridines of the formula (I) are known per se and are suitable for the production of different compounds, in particular of insecticides and herbicides.
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