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1.
P. Voss C. Meinicke E. Popowski H. Kelling 《Advanced Synthesis \u0026amp; Catalysis》1978,320(1):34-42
Preparation and Reactions of α-Halogenobenzyl-silanes α-Bromobenzyl-dimethylchlorosilane 3 , bis-(α-bromobenzyl)-dimethylsilane 8 and the corresponding α-chlorobenzyl-compounds 5 and 13 have been prepared by reaction of benzyl-dimethylchlorosilane 1 resp. dibenzyl-dimethylsilane 2 with N-bromosuccinimid and sulfurylchlorid. The α-halogenobenzyl-dimethylchlorosilanes 3 and 5 have been treated with water, alcohols and phenol, to give the corresponding silanols 15 and 16 , siloxanes 17 and 18 , alkoxy- and phenoxysilanes 19 and 20 . Reactions of 3 with brenzcatechin, o-aminophenol and o-aminobenzylalcohol give 6- resp. 7- membered silaheterocycles 21 – 23 . 相似文献
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β-Thiocyanato-vinylcarbonyl Compounds. II. Preparation of 4,5-Substituted Isothiazoles Z-β-Thiocyanato-vinylaldehydes cyclize with liquid ammonia to isothiazoles. A new synthesis for 4- and/or 5-alkyl, cycloalkyl- or aryl-substituted isothiazoles by direct reaction of Z/E-β-chlorovinylaldehydes with ammonium thiocyanate in boiling acetone is presented. As a third procedure, the reaction of β-thiocyanato-vinylaldehydes with NH4SCN in acetone is convenient. The obtained 4,5-substituted isothiazoles were characterized by their u. v. and n. m. r. spectra and perchlorates. 相似文献
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B. Schulze R. Brmer E. Kleinpeter M. Mühlstdt 《Advanced Synthesis \u0026amp; Catalysis》1976,318(5):795-800
β-Thiocyanato-vinyl-carbonyl Compounds. III 1H-NMR Investigations of β-Thiocyanato-vinylaldehydes The 1H-NMR spectra of some alkyl- and phenylsubstituted Z/E-isomeric β-thiocyanato-vinylaldehydes are represented. The assignment for Z/E-isomers is made using the chemical shifts of the CHO-protons and paramagnetic shift experiments. The discussion of the ΔEu-values allows to determine the conformation of the CHO-group. The main products in the case of the alkyl-substituted β-thiocyanato-vinylaldehydes are the Z-isomeric compounds which fact is attributed to mechanistic and electronic effects. 相似文献
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β-Fur-2-yl-α-halogenacrylonitriles. IV. Reactions of β-Fur-2-yl-α-halogenacrylonitriles with Alcohols and Phenols β-Fur-2-yl-α-halogenacrylonitriles 1a – c react with alcohols and phenols to yield β-fur-2-yl-β-alkoxyacrylonitriles and β-fur-2-yl-β-aroxyacrylonitriles 2a – k respectively. With ethylene glycol α-[2-(fur-2-yl)-1, 3-dioxolan-2-yl]acetonitriles 3a, b are formed. 相似文献
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Reactions of β-Chlorovinylaldehydes. IV. Syntheses of 2-Formylmethylene-2H-1-benzopyranes and Benzopyrylocyaninedyes from β-Chlorovinylaldehydes α-Alkyl-β-chlorocrotonaldehydes react with salicylaldehyde in methanolic solution of potassium hydroxide forming 2-formyl-methylene-2H-1-benzopyranes 1 . The corresponding benzopyryliumsalts 2 which are easily available from 1 and strong acids, exist in the enolic form. They react at room temperature in alcoholic solution with elimination of ethyl formiate, yielding dark blue compounds which were identified as 2,2′-benzopyrylotrimethincyanindyes 3 . The structure of 3 has been elucidated by means of 1H-n.m.r.-spectra. 相似文献
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K. Schulze A.-K. Habermann H. Uhlig K. Wyßuwa 《Advanced Synthesis \u0026amp; Catalysis》1993,335(8):687-693
α-Methylated Fencholenic and α-Campholenic Aldehyde – Synthesis and Reactions The syntheses of α-methylated fencholenic ( 6a ) and α-campholenic aldehyde ( 6b ) via the corresponding azomethines ( 5 ) are reported. Aldol condensations of 6a, b with following reductions give the allylic alcohols ( 12–16 ) and hydrogenation the saturated alcohols ( 17–21 ) with strong woody odors, some of the allylic alcohols resembling that of sandal wood. Simple reduction or oxidation of 6a, b give the alcohols ( 24, 27 ), ethers ( 26 ), esters ( 23, 25, 28 ) and ketones ( 29 ) which have interesting woody odors with spicy, earthy and herbaceous notes. 相似文献
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β-Thiocyanatovinylcarbonyl Compounds. XI. Unusual Substituent Effects in the Mass-spectrometrical Fragmentation of β-Thiocyanatovinylaldehydes The mass spectra of homologous Z/E-isomers and constitutional isomers of β-thiocyanatovinylaldehydes are discussed. The main fragmentation consisting of HCN-loss from the molecular ion is influenced by the substituents so that the constitutional and steric isomers can be clearly distinguished by the \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm M - HC}\left. {\overline {\, {\rm N} \,}}\! \right| + /{\rm M + }^ \cdot $\end{document} ratio. Alkyl homologues with a hydrogen atom in γ-position to the aldehyde group show an unusual intensive CN-radical loss due to a „hidden hydrogen rearrangement”︁, which was proved by deuteration experiments. 相似文献
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Manfred Mühlstdt Hansjürgen Meinhold Dieter Martinetz Eberhard Neumann 《Advanced Synthesis \u0026amp; Catalysis》1982,324(4):631-638
Preparation and Reactions of β-Oxosulfenyl Chlorides. II. Direct Chlorosulfenylation of Disubstituted Acetaldehydes by Sulfur Dichloride The reaction of dialkylacetaldehydes ( 1a , b ) with sulfur dichloride yields the corresponding β-oxosulfenylchlorides ( 2a , b ). Examples for addition- and substitution-reactions of 2a , b are described. 相似文献
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K. Jhnisch H. Seeboth E. Krause D. R. Callejas 《Advanced Synthesis \u0026amp; Catalysis》1984,326(4):556-560
β-Fur-2-yl-α-halogenacrylonitriles. I. Preparation of β-Fur-2-yl-ß-aminoacrylonitriles and β-Fur-2-yl-α-aminoacrylonitriles β-Fur-2-yl-α-halogenacrylonitriles 1 react with secondary amines to yield β-fur-2-yl-ß-aminonitriles 2 and β-fur-2-yl-α-aminoacrylonitriles 3 . The 1 H-n.m.r. spectra of the E/Z isomers are discussed. 相似文献
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K. Schulze K. Wyßuwa H. Trauer A.-K. Habermann 《Advanced Synthesis \u0026amp; Catalysis》1993,335(6):537-543
Synthesis and Reactions of β-Campholene Compounds In contrast to the well known α-campholenic ( B ) and fencholenic compounds ( C ) little is known about β-campholenic derivatives ( A ) because of their difficult accessibilitiy. β-Campholenic compounds ( A ) can be obtained: (1) by Baeyer-Villiger oxidation of camphor via lactone 7 and β-dihydrocampholenic lactone ( 5 ); (2) by Beckmann fragmentation of camphor oxime via α-( 2 ) and β-campholenic nitril ( 3 ) and the lactone 5 ; and ( 3 ) by acid catalysed rearrangement of α-campholenic derivatives ( B , 17a , b ). The β-analogous brahmanol ( 14 ) can be synthesized by the reaction of the β-campholenic bromide ( 11 ) with methyl diethyl malonate or by rearrangement of brahmanol. 相似文献
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β-Fur-2-yl-α-halogenacrylonitriles. VII. Reactions of β-(5-Bromo-fur-2-yl)-α-bromoacrylonitriles with Mercaptans, Thiourea and Thiourea Derivatives β-(5-Bromo-fur-2-yl)-α-bromoacrylonitrile 1 reacts with ethylmercaptan to yield β-(5-bromo-fur-2-yl) β-ethylthioacrylonitrile 3 . With thiourea β,β′-thio-bis[β-(5-bromo-fur-2-yl)]-acrylonitrile 2 is formed. The pyrimidines 4 and 5 have been prepared by the reaction of 1 with s-methylthiourea and 2-aminothiazole, respectively. The structure of the new compounds were determined by means of x-ray analysis, 1H-n.m.r., 13C-n.m.r. and mass-spectroscopy. 相似文献
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Synthesis and Reactions of 2-Arylamino-3-nitroquinolines Condensation of 1-nitro-2,2-bis(methylthio)ethylene with esters of anthranilic acid yields 2-arylamino-3-nitro-4-quinolones. 2 . Analogously, from 1-nitro-2-anilino-2-methylthioethylene and o-aminoketones, 2-anilino-3-nitroquinolines 4 are obtained which can be reduced to 2-anilino-3-amino-quinolines 7 . The latter undergo cyclizations by usual methods to yield substituted triazolo-, imidazolo-, diazepino- and pyrazino-quinolines 9–12 . Reaction of ethyl-2-aminothiophene-3-carboxylates with 1-nitro-2-anilino-2-methylthio-ethylene affords 2-anilino-3-nitrothieno[2,3-b]-4-pyridones 5 . 相似文献