AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

The reaction of azomethine dyes (1a - g) with malonodinitrile (2) gives dicyanomethylene-pyrazolin-5-one (4) which immediately reacts with the eliminated anilines by HCN-amine exchange giving the deeply coloured arylamino-cyanomethylene-pyrazolinones (5a-g). Structural investigations and a study of the absorption characteristic are described.

Synthesis of Substituted 2-Nitrophenylhydrazones of 2-Oxodicarboxylic Acid Esters and Investigation of Their Tautomerism and Absorption Behaviour 32 Substituted 2-nitrophenylhydrazones of diethyl oxalacetate, 2-oxoglutaric acid and its 1-mono- and 1,5-dialkyl esters, resp., have been synthesized from substituted 2-nitrophenylhydrazines and 4,6-dinitro-1,3-dihydrazinobenzene and the carbonyl compounds named above. 1H-n.m.r. spectra prove all products to have the constitution of hydrazones and not that of azo compounds or enhydrazines and also allow the assignation of the E- and Z-configuration, resp., to the hydrazone diastereomers. The absorption behaviour of all hydrazones is discussed with comparison of the different substitution patterns. Unexpectedly, the 4,6-dinitro-1,3-bishydrazones 27 – 32 show very high lg ϵmax values (at about 4.8) due to their crossed two chromophoric systems.

A high performance liquid chromatographic procedure on 5 μm RP-18 was developed for the separation of the four possible cis-trans isomers of tetramethyl-calix[4]arenoctol, and of their octaacetates, and their octamethyl ethers.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInformVolume 21, Issue 19 Reviews ChemInform Abstract: The Structure of Alicyclic Molecules with Saturated Six-Membered Rings: Dedicated to the One-Hundredth Anniversary of the Structure of Cyclohexane Established by Hermann Sachse G. MANN, G. MANN Sekt. Chem., Karl-Marx-Univ. Leipzig, DDR-7010 LeipzigSearch for more papers by this author G. MANN, G. MANN Sekt. Chem., Karl-Marx-Univ. Leipzig, DDR-7010 LeipzigSearch for more papers by this author First published: May 8, 1990 https://doi.org/10.1002/chin.199019352Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume21, Issue19May 8, 1990 RelatedInformation

Synthesis of Benzylideneaminopyrazoles and Bispyrazolopyridines5‐Aminopyrazoles 1a–e react with aromatic aldehydes in boiling ethanol to yield azomethines 2a–n. Bispyrazolopyridines 7a–f are obtained by the reaction of 2a–f with an excess of aminopyrazole at higher temperatures via bisaminopyrazoles 5 and bispyrazolodihydropyridines 6. Structure and configuration of the products are assigned by n.m.r.‐spectroscopy. Reactions with replacement of the arylidene group on azomethine 2b suggest that the transformation of azomethines to bisaminopyrazoles occurs through a mechanism involving addition of the CH‐acidic component, with subsequent elimination of aminopyrazole.

AbstractThe aminopyrazoles (I) react with aromatic aldehydes in a 1:1 molar ratio to give azomethines of type (III) (13 examples).

AbstractThe title compound which can be prepared, e.g., from (I) and (II) had been assigned structure (IV) by Westoeoe (1953); it was later found that in solution an equilibrium exists between the title compound, assumed to be (IV), and an isomer.

The reaction of primary and secondary amines with 4-arylidenepyrazolones gives the corresponding ammonium salts of 4,4′-benzylidenebis-5-pyrazolone derivatives but not adducts on the exocyclic C=C bond as was previously believed.

ChemInformVolume 19, Issue 51 Heterocyclic Compounds ChemInform Abstract: Reaction of 4-Benzylidene-3-methyl-1-phenylpyrazol-5-ones with Amines. G. MANN, G. MANN Karl-Marx-Univ., DDR-7010 LeipzigSearch for more papers by this authorD. BENDLER, D. BENDLER Karl-Marx-Univ., DDR-7010 LeipzigSearch for more papers by this authorL. HENNIG, L. HENNIG Karl-Marx-Univ., DDR-7010 LeipzigSearch for more papers by this authorM. A. KUZNETSOV, M. A. KUZNETSOV Karl-Marx-Univ., DDR-7010 LeipzigSearch for more papers by this authorV. N. BELOV, V. N. BELOV Karl-Marx-Univ., DDR-7010 LeipzigSearch for more papers by this author G. MANN, G. MANN Karl-Marx-Univ., DDR-7010 LeipzigSearch for more papers by this authorD. BENDLER, D. BENDLER Karl-Marx-Univ., DDR-7010 LeipzigSearch for more papers by this authorL. HENNIG, L. HENNIG Karl-Marx-Univ., DDR-7010 LeipzigSearch for more papers by this authorM. A. KUZNETSOV, M. A. KUZNETSOV Karl-Marx-Univ., DDR-7010 LeipzigSearch for more papers by this authorV. N. BELOV, V. N. BELOV Karl-Marx-Univ., DDR-7010 LeipzigSearch for more papers by this author First published: December 20, 1988 https://doi.org/10.1002/chin.198851196Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume19, Issue51December 20, 1988 RelatedInformation

ChemInformVolume 19, Issue 23 Physical Organic Chemistry ChemInform Abstract: Compression Effects of Sterically Hindered Methyl Groups of Derivatives of C-4-Substituted 2-Pyrazolin-5-ones L. HENNIG, L. HENNIG Sekt. Chem., Karl-Marx-Univ., DDR-7010 LeipzigSearch for more papers by this authorD. BENDLER, D. BENDLER Sekt. Chem., Karl-Marx-Univ., DDR-7010 LeipzigSearch for more papers by this authorR. HAESSNER, R. HAESSNER Sekt. Chem., Karl-Marx-Univ., DDR-7010 LeipzigSearch for more papers by this authorG. MANN, G. MANN Sekt. Chem., Karl-Marx-Univ., DDR-7010 LeipzigSearch for more papers by this author L. HENNIG, L. HENNIG Sekt. Chem., Karl-Marx-Univ., DDR-7010 LeipzigSearch for more papers by this authorD. BENDLER, D. BENDLER Sekt. Chem., Karl-Marx-Univ., DDR-7010 LeipzigSearch for more papers by this authorR. HAESSNER, R. HAESSNER Sekt. Chem., Karl-Marx-Univ., DDR-7010 LeipzigSearch for more papers by this authorG. MANN, G. MANN Sekt. Chem., Karl-Marx-Univ., DDR-7010 LeipzigSearch for more papers by this author First published: June 7, 1988 https://doi.org/10.1002/chin.198823053Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume19, Issue23June 7, 1988 RelatedInformation

ChemInformVolume 18, Issue 40 Heterocyclic Compounds ChemInform Abstract: A Convenient Synthesis of Novel 1,3,4-Substituted 2-Pyrazolin-5-ones. D. SICKER, D. SICKER Sekt. Chem., Karl-Marx-Univ., DDR-7010 LeipzigSearch for more papers by this authorW. + BOEHLMANN, W. + BOEHLMANN Sekt. Chem., Karl-Marx-Univ., DDR-7010 LeipzigSearch for more papers by this authorD. BENDLER, D. BENDLER Sekt. Chem., Karl-Marx-Univ., DDR-7010 LeipzigSearch for more papers by this authorG. MANN, G. MANN Sekt. Chem., Karl-Marx-Univ., DDR-7010 LeipzigSearch for more papers by this author D. SICKER, D. SICKER Sekt. Chem., Karl-Marx-Univ., DDR-7010 LeipzigSearch for more papers by this authorW. + BOEHLMANN, W. + BOEHLMANN Sekt. Chem., Karl-Marx-Univ., DDR-7010 LeipzigSearch for more papers by this authorD. BENDLER, D. BENDLER Sekt. Chem., Karl-Marx-Univ., DDR-7010 LeipzigSearch for more papers by this authorG. MANN, G. MANN Sekt. Chem., Karl-Marx-Univ., DDR-7010 LeipzigSearch for more papers by this author First published: October 6, 1987 https://doi.org/10.1002/chin.198740169Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume18, Issue40October 6, 1987 RelatedInformation

Synthesis of Substituted N‐Hydroxylactams, Lactams, Quinoline‐N‐oxides, and Quinolines by Catalyzed Reductive Cyclization of 2‐Nitrocinnamoyl Derivatives with Hydrogen/Platinum BlackSubstituted nitrobenzenes 1a–1m, consisting of two series of 6 analogous compounds, containing the structural unit of an α,β‐substituted 2‐nitrocinnamoyl group have been reductively cyclized by means of hydrogen in the presence of platinum black catalyst to form four types of heterocycles: N‐hydroxylactams 2a and b, lactams 3 and 4, quinoline‐N‐oxides 5a–d, and quinolines 6a and b. The type of substituents at the 2‐nitrocinnamoyl group is of significance for the type of heterocycle formed in this reaction. It is of special interest that by the use of the reduction system hydrogen/platinum black the probability to obtain N‐hydroxylactams or quinoline‐N‐oxides, which are difficult to obtain by alternative procedures, becomes much higher than by the use of many reducing agents acting noncatalytically.

AbstractThe reaction of the pyrazoles (I) with the anilines (II) yields the quinoxalines (III) which show intense fluorescence in organic solvents.

Oxidative Coupling of 5‐Aminopyrazoles with p‐Phenylenediamines By oxidative coupling of 5‐amino‐3‐methyl‐1‐phenyl‐pyrazole 4 with N,N‐diethyl‐p‐phenylenediamine the 4‐(4‐N,N‐diethylamino‐phenylimino)‐3‐methyl‐1‐phenyl‐2‐pyrazolin‐5‐imin 5 is formed. 5 is oxidized very easily to the 1H‐pyrazolo[3,4‐b]quinoxaline 6a . The Z/E‐isomerism of the azomethine dye is investigated by dynamic n.m.r.‐spectroscopy. 1H‐Pyrazolo[3,4‐b]quinoxalines (6a–d) are also formed by reaction of 1,3‐disubstituted 5‐aminopyrazoles with p‐nitroso‐dialkylanilines.