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  • 1
    Electronic Resource
    Electronic Resource
    Cyclisations par l'intermédiaire de fonctions phénylthioet phénoxy-carbamyle. I. Diphényl-1,2-alcoyl-5-dioxo-3,6-hexahydro-triazines-1,2,4 (1969)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 52 (1969), S. 282-291 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The N-(p-nitrophenoxy-carbonyl) and N-(phenylthio-carbonyl) derivatives of α-amino-acyl-hydrazides cyclize in presence of diazomethane, yielding hexahydro-1, 2, 4-triazines with simultaneous formation of p-nitro-anisole or thio-anisole respectively. The molecules with a phenoxycarbonyl function such as N-(phenoxycarbonyl)-glycyl-(N, N′-diphenylhydrazide) give the corresponding ring products and anisole only in solvents with high dielectric constant (e.g. nitromethane). The phenylthio-carbonyl derivatives give the same ring products in presence of lead acetate by the intervention of HO-. The p-nitrophenoxycarbonyl derivatives give rise to the same cyclisations in the presence of pyridine by the intermediate of carbamyle-pyridinium ion acting as electrophile.These different types of intramolecular reactions are illustrated by the formation of 1, 2-diphenyl-5-alcoyl-3, 6-dioxo-1, 2, 4-hexahydro-triazines.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19690520129
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  • 2
    Electronic Resource
    Electronic Resource
    Un nouveau type de réarrangement de SMILES: 1a transformation du N-p-nitrophénoxy-carbonyl-hydrazobenzène en N-p-nitrophényl-hydrazobenzène (1964)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 47 (1964), S. 1047-1052 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: En présence d'une base, le N-p-nitrophénoxycarbony1-hydrazobenzène subit une transposition en N-p-nitrophényl-hydrazobenzène avec Climination de CO,. Cette transformation présente une grande analogie avec le réarrangement de SMILES, dont le OH- schéma est \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm HY} - {\rm C} - {\rm C} - {\rm X} - {\rm Ar}{\rm Ar Y} - {\rm C} - {\rm C} - {\rm X H(X = O, SO}_{\rm 2},{\rm SO, S; Y = } - {\rm OH, } - {\rm SH, } - {\rm NHR, } - {\rm CONHR)} $\end{document}. Dans notre cas, × = 0 et HY—C est remplacé par NH(C, H5)-N.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19640470415
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  • 3
    Electronic Resource
    Electronic Resource
    Réactions du diazométhane III. Etude de la réaction d'insertion entre diazométhane et phénylcarbamates: comportement de la N-(phénoxy-carbonyl)-aniline et de la N-(p-nitrophénoxy-carbonyl)-aniline (1968)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 51 (1968), S. 398-402 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Diazomethane reacts with N-(p-nitrophenoxy-carbonyl)-aniline giving on the one hand p-nitroanisole and phenylisocyanate, the latter being transformed into N-phenyl-β-propiolactam, and on the other hand N-(p-nitrophenoxy)-acetanilide by insertion. N-(phenoxy-carbonyl)-aniline does not react. The insertion reaction seems to depend on the heterolysis of the bond between the oxygen of the p-nitrophenoxy group and the carbamic carbonyl function, which is strongly polarized (existence of a mesomeric nitro-phenoxonium). The insertion is equally influenced y the nature of the radical R attached to the carbamic nitrogen: with R = —CH2COOC2H5 the reaction yields only isocyanate, with R = —C6H5 it yields at the same time the isocyanate and the insertion product.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19680510220
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  • 4
    Electronic Resource
    Electronic Resource
    Réactions du diazométhane. I. Transformation de la fonction N-phénylthio-carbonyle (C6H5SCO-NH-R) avec production d'isocyanate (O—C=N—R) par élimination bimoléculaire (1965)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 48 (1965), S. 2005-2022 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Diazomethane transforms N-(phenylthio-carbonyl)-amino acid esters or amides into the corresponding N-carbonyl derivatives, similarly it converts N-(phenylthio-carbonyl)-butyl-1-amine into butyl-isocyanate. Solvents with a high dielectric constant (e. g. nitromethane, ethanol) favour this transformation. The analogous but N-substituted N-(phenyloxy-carbonyl)-amino acid esters are not modified by diazomethane. This new reaction appears to proceed by a bimolecular elimination (E2), where the transition state leads very rapidly to the formation of an isocyanate on the one hand and thio-anisole on the other.
    Additional Material: 7 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19650480822
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  • 5
    Electronic Resource
    Electronic Resource
    Réactions du diazométhane II. Transformation de la fonction N-(phénylthio-carbonyle) de la N-(phénylthio-carbonyl)-aniline avec production de phénylthio-acétanilide par insertion (1965)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 48 (1965), S. 2023-2026 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reaction of diazomethane with N-(phenylthio-carbonyl)-aniline gives on the one hand phenylthio-acetanilide and on the other N-phenylpropiolactame. This β-lactame arises by the (known) addition of two molecules of diazomethane to phenyl isocyanate, the latter resulting by an elimination (E2) of the thiophenyl residue in the form of thio-anisole, originating from the direct action of diazomethane on the N-(phenylthio-carbonyl) group. The acetanilide is produced by the insertion of a methylene group (furnished by diazomethane) with fissure of the sulphur-carbon linkage in the grouping It is probable that the mechanism of the transformation involves, as a first step, a bimolecular nucleophilic substitution on the carbonyl of the carbamate function, yielding a diazonium cation and a thiophyl anion; in a second step the diazonium ion reacts with the anion C6H5S⊖, establishing the linkage —S—CH2— with elimination of nitrogen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19650480823
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