Condensation of β-keto esters with 5-aminopyrazoles unsubstituted in position 1 gives 7-oxopyrazolo[1,5-a]pyrimidines.

Only one isomer, 5-methyl-3-phenyl-1-pyrazolylsuccinic acid, is formed on addition of 3(5)-methyl-5(3)-phenylpyrazole to the double bond of maleic anhydride.

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By condensation of various symmetric β-diketones with a series of 5-aminopyrazoles that are unsubstituted at the position 1, we have obtained a series of pyrazolo[1,5-a]pyrimidines that are of interest as physiologically active compounds. Hexafluoroacetylacetone reacts in another direction, forming pyrazolo[4,5-b]pyridine.

With the aim of preparing new biologically active compounds a series of N (1) -substituted 5-amino-3-methylpyrazoles has been obtained from β-aminocrotononitrile and mono-substituted hydrazines.

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The experimental data were refined and the yields were improved significantly in cyclization of pyrazolones-5 into tripyrazolylenes-1,5 with phosphorus oxychloride.

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.

N-Substituted pyrazoles with a free 4-position on the ring and not containing electron-acceptor substituents easily react with o-chlorobenzenesulfonylisocyanate according to an electrophilic substitution scheme, forming 4-o-chlorobenzenesulfonylcarbamoyl derivatives.

Nitrogen-containing π-rich heterocycles under mild conditions are acylated by o-chlorobenzene-sulfonylisocyanate, forming C-arylsulfonylcarbamoyl derivatives; O- and S-containing heterocycles do not react under these conditions.

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.

Halogenation, nitration, and sulfonation of previously obtained tris(1,5-pyrazolediyls) proceeds at position 4 of the pyrazole nucleus with the formation of symmetrical tris(4-substituted 1,5-pyrazolediyls) in quantitative yield. However, only a monoformyltrispyrazolediyl is obtained in the Vilsmeier reaction. An x-ray structural investigation has been carried out on the trispyrazolediyl nucleus of compound (1c).

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.

1,5-Tripyrazolylenes were prepared with satisfactory yields by the reaction of 5-pyrazolones unsubstituted at the nitrogen atom with an equimolar amount of POCl3 in open vessels together with 5-chloro derivatives (Michaelis reaction).

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.

In the reaction of o-chlorosulfonyl isocyanate with imidazole, pyrazoles, and pyrazolines with a free NH group of the nucleus under mild conditions, N-acylation takes place with the formation of a heterocyclic containing, at the nitrogen atom of the nucleus, an o-Cl-C6H4SO2NHCO- group which hydrolyzes very easily in the case of pyrzoles.

Benzopyrylium dye BDBP was found to be an effective uncoupler of oxidative phosphorylation. It stimulates state 4 respiration of mitochondria 2-fold at about 2 microM, reveals a maximum stimulation (8-fold) at 30 microM and inhibits the respiration at higher concentrations. BDBP is also an effective proton (hydroxyl) carrier through bilayer lipid membranes (BLM) as is seen from the electrical properties of BLM with BDBP. Picrate enhances the effects of BDBP on the mitochondrial respiration and BLM conductance. The BDBP activities are accounted for by formation of dimers and complexes with picrate.

The basicity of a series of 3-formyl-4,7-diaminocoumarins and their azomethine derivatives was studied. By using PMR data, it was determined that primary protonation of most aldehydes affects the nitrogen atom in the 7 position and, in the case of azomethines, the nitrogen atom of the azomethine group.