Über die acetolysenprodukte der cyanhydrine von 4-pyridazoin und 4-pyridoin: Struktur und ungewöhnliche reaktivität 9. Mitteilung über pyridazine

4-Pyridazoinecyanohydrin was found to be converted into the 1,4-dihydropyridazine derivative 2a on treatment with acetic anhydride. Structures of 2a and the corresponding 4-pyridine derivative 2b were assigned on the basis of spectroscopic data. Chromatography of 2a on silica gel using methanol as eluent yielded methyl 4-pyridazinecarboxylate. The pyridine derivative 2b under similar conditions was converted into a mixture of methyl isonicotinate and 4-pyridinylmethyl acetate. Mechanisms of these unexpected reactions are discussed.     

Parton distribution functions at LO,NLO and NNLO with correlated uncertainties between orders

Sets of parton distribution functions (PDFs) of the proton are reported for the leading (LO), next-to-leading (NLO) and next-to-next-to-leading-order (NNLO) QCD calculations. The parton distribution functions are determined with the HERAFitter program using the data from the HERA experiments and preserving correlations between uncertainties for the LO, NLO and NNLO PDF sets. The sets are used to study cross-section ratios and their uncertainties when calculated at different orders in QCD. A reduction of the overall theoretical uncertainty is observed if correlations between the PDF sets are taken into account for the ratio of \(WW\) di-boson to \(Z\) boson production cross sections at the LHC.     

1,2-Dipyridazinyl-äthen- und-äthan-1,2-diole aus Pyridazin-carbaldehyden

Treatment of pyridazine-4-carboxaldehyde with catalytic amounts of KCN results in formation of pyridazine-4-carboxylic acid and two stereoisomeric diols (4,5). The configurations of4 and5 are explained on basis of the¹H-NMR-spectra, the mechanism of reaction is discussed. Pyridazine-3-carboxaldehyde (10) reacts with HCN to form the addition product of10-cyanhydrine to10 (11). HCN-elimination from11 yields the enediol12 which by oxygen is oxidized to pyridazine-3-carboxylic acid or its methyl ester.

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Herrn Univ.-Prof. Dr.M. Pailer mit den besten Wünschen zum 65. Geburtstag gewidmet.

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5. Mitt.:G. Heinisch, E. Luszczak undM. Pailer, Mh. Chem.105, 763 (1974).     

Thermisch induzierte Disproportionierung von Pyridazinyl-4-carbinolen

Pyridazinyl-4-carbinols (e.g.4, 9a, 9b) are found to dismutate at elevated temperatures yielding 4-alkyl-pyridazines and pyridazinyl ketones. This explains formation of unusual products in certain condensation reactions of pyridazine-4-carboxaldehyde. The mechanism of dismutation is discussed, IR-,¹H-NMR- and mass spectral data of the new pyridazine derivatives4, 5, 6, 8, 11a are presented.

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4. Mitt.:G. Heinisch, A. Jentzsch undM. Pailer, Mh. Chem.105, 648 (1974).