β-Fur-2-yl-α-halogenacrylonitrile. IV. Reaktionen von β-Fur-2-yl-α-halogenacrylonitrilen mit Alkoholen und Phenolen

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.     

β-Fur-2-yl-α-halogenacrylonitrile. I. Darstellung von β-Fur-2-yl-ß-aminoacrylonitrilen und β-Fur-2-yl-α-aminoacrylonitrilen

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.     

β-Fur-2-yl-α-halogenacrylonitrile. VIII. Konformationsuntersuchungen an substituierten β-Fur-2-yl-acrylonitrilen

β-Fur-2-yl-β-halogenacrylonitriles. VIII. Investigations of the Conformation of Substituted β-Fur-2-yl-acrylonitriles X-ray analysis, n.m.r.-investigations in the presence of Eu(FOD)₃ and NOE-measurement indicate, that the E-isomer of β-substituted β-fur-2-yl-acrylonitriles exist in the s-cis conformation, whereas the E-isomer of the α-substituted β-fur-2-yl-acrylonitriles prefer the s-trans-conformation. The influence of the configuration and conformation on the chemical shift of the H-3-furan protons is discussed.     

Furylvinylhalogenide. X [1]. Reaktionen von β-Fur-2-yl-β-chlor-α-cyanacrylsäurederivaten mit Hydrazinen

Furylvinylhalides. X. Reactions of β-Fur-2-yl-β-chloro-α-cyanoacrylic Acid Derivatives with Hydrazines β-Fur-2-yl-β-chloro-α-cyanoacrylic acid derivatives 3 react with hydrazines yielding 3-fur-2-yl-5-aminopyrazoles 5 or 3-fur-2-yl-4-cyanpyrazolin-5-ones 6 . In some cases the β-hydrazino-α-cyanoacrylic acid derivatives 4 , could be isolated.     

Furylvinylhalogenide. IX. Reaktionen von β-Fur-2-yl-β-chlor-α-cyanacrylsäureestern mit Aminen

Furylvinylhalides. IX. Reactions of β-fur-2-yl-β-chloro-α-cyanoacrylates with amines β-Fur-2-yl-β-chloro-α-cyanoacrylates 4 react with amines to yield β-Fur-2-yl-β-amino-α-cyanoacrylates 5 . The ¹H-n.m.r. spectra of 5 are discussed.     

β-Fur-2-yl-α-halogenacrylonitrile. VII. Reaktionen von β-(5-Brom-fur-2-yl)-α-bromacrylonitril mit Mercaptan,Thioharnstoff und Thioharnstoffderivaten

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.     

Reaktionen von β-Chlorvinylaldehyden. IV [1]. Synthesen von 2-Formylmethylen-2H-1-benzopyranen und Benzopyrylocyaninfarbstoffen aus β-Chlorvinylaldehyden

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.     

Addition von α-Ketoenaminen an 2-Acetyl-p-benzochinon

Addition of α-Ketoenamines to 2-Acetyl-p-benzoquinone Addition of 2-morpholino-2-cyclohex-1-en-one 2 to 2-acetyl-quinone 1 yields benzo[c][4 H]chromen-4,7,10-trion 4 which is unstable and rearranges to 5. 4 is converted to 3-(2,5-dihydroxy-phenyl)-2-morpholino-2-cyclohex-1-en-on 3 thermically and to dibenzo[b,d]furan-4-on 7 acid catalyzed. The structure of 7 is secured by independent synthesis. Dibenzo[b,d]furan-4-on 14 is the product of reaction from 2-(p-toluidino)-2-cyclohex-1-en-on 9 and 1 with benzo[c][4 H]chromen-4,7,10-trion 10 as intermediate. By proton catalysis 5-acetyl-6-hydroxy-carbazol-1-on 13 and 4-oxo-cyclohexa[c]isochinolinium hydrochlorid 15 is obtained from 10 . 1 H-cyclopenta[d]furan-3-on 17 is formed by addition of 2-(p-toluidino)-2-cyclopent-1-en-on 16 to 1 . It is rearranged by proton catalysis to 3-oxo-1 H-cyclopenta[c]isochinolinium salt 18 . Reaction of cyclopentan-1,2-dione and 1 yields 3 aH-cyclopenta[c]isochromen-3,6,9-trion 20 , rearranging to 1 H-cyclopenta[b]benzo[d]furan-3-on 21 . The stereochemistry of adducts is discussed in connection with the course of the reaction, spectroscopical evidence, molecular modelling and calculation of HOMO/LUMO and AO-coefficients.     

13C-NMR-Spektroskopie von bromierten 3-Keto- und 3β-Acetoxy-5α-cholestan-Verbindungen

¹³C-NMR Spectroscopic Investigations of Brominated 3-Keto- and 3β-Acetoxy-5α-cholestane Derivatives The chemical shifts of some brominated 3-keto- and 3β-acetoxy-5α-cholestane derivatives are determined. The substituent effects of bromine atoms on chemical shifts (SCS) and their additive behaviour, especially γ-SCS, are discussed.     

Radiation-induced copolymerization of α,β,β-trifluoroacrylonitrile with α-olefin

Homopolymerization and copolymerization of α,β,β-trifluoroacrylonitrile (FAN) with γ-olefins were carried out in bulk by γ-ray irradiation at 25°C. FAN gives very small quantities of brown and greasy low molecular weight polymer. Cyano groups in FAN polymer were found to be readily hydrolyzed to acid amide groups in the atmosphere. FAN was found to copolymerize with ethylene, propylene, and isobutylene via a radical mechanism to form equimolar copolymers in a wide range of monomer compositions. The polymerization rate increases linearly with FAN fraction in the monomer mixture. These copolymers are also hydrolyzed in the atmosphere, and the hydrolysis proceeds with more difficulty for the copolymer with higher α-olefin. The reactivity ratios r₁ (FAN) and r₂ (α-olefin) were determined to be 0.01 and 0.12 for the FAN/ethylene copolymerization and 0.01 and 0.07 for the FAN/propylene copolymerization. These results confirm that an alternating copolymerization takes place in the FAN/α-olefin system.     

Synthese von β-Nitroalkenyl-benzylphosphorylderivaten

Synthesis of β-Nitroalkenyl-benzylphosphorylderivatives Starting from methoxy-chlormethylbenzaldehydes 2 the benzylphosphonates and -phosphinoxides 3 A, B had been synthesized, which could be transformed via the Schiff-bases 4 A, B to phosphorylated nitrostyrenes 5 A, B and nitropropenylbenzenederivatives 6 A, B . The phosphonoacids 3 Ad, 3 Bd and 6 Ba could be prepared from the corresponding esters by direct acidic hydrolysis or by dealkylation with trimethylsilylbromide and hydrolysis of the trimethylsilylesters respectively.     

Partialsynthesen von Cardenoliden und Cardenolid-Analogen. I. α,β- und β,γ-ungesättigte Lactonring-methylierte Cardenolide

Partial Syntheses of Cardenolides and Cardenolide Analogues. I. α,β- and β,γ-Unsaturated Lactone Ring-Methylated Cardenolides Base-catalyzed methylation of digitoxigenin 1a with methyl iodide and sodium hydride in DMF leads to the α,β-unsaturated cardenolides 2–5 and, after rearrangement of the CC-double bond, to the β,γ-unsaturated cardenolides 6 and 7 . Opening of the lactone ring results in the formation of 8 . Allylic oxidation of 4b affords the 14,21-epoxide 10 . Only the 22-methyl derivative 4a and its 3-O-tridigitoxoside 4d show strong biological effectivity, whereas methylation at 21R- or 21S-position results in considerable loss in activity.     

Synthesis of α, α′, β-trideuterovinyl acetate

Reaction conditions for the synthesis of α, α′, β-trideuterovinyl acetate by the continuous vapour phase catalytic reaction of deuteroacetylene and acetic acid-d (CH₃COOD) are described.