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Hydrazine Derivatives (hydrazine + derivative)
Selected AbstractsChemInform Abstract: Use of Polyanions for Alkylation of Hydrazine Derivatives.CHEMINFORM, Issue 16 2008Aleksei Bredihhin Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 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. [source] Synthesis of some novel 3,7-dimethyl-4H -pyrazolo[5,1-c][1,2,4]triazin-4-onesJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 3 2001Ahmed A. El-Barbary Some novel 3,7-dimethyl-6H -pyrazolo[5,1-c][1,2,4]triazin-4-ones were prepared (3a-g). Compounds 3a,b were treated with hydrazines to afford various products 7a,b, 8a,b, 9 and lla,b depending on the type of hydrazine derivative and reaction conditions. The benzoyloxyimino-pyrazolo[5,1-c][1,2,4]triazines (13a,b) were synthesized by refluxing of compounds 3a,b with hydroxylamine hydrochloride to afford the corresponding oxime derivatives followed by treatment with benzoyl chloride. [source] Transformation of Amino Acids into Nonracemic 1-(Heteroaryl)ethanamines by the Enamino Ketone MethodologyHELVETICA CHIMICA ACTA, Issue 1 2006Samo Pirc Abstract N -Protected L -phenylalanines 1a,b were transformed, via the corresponding Weinreb amides 2 and ethynyl ketones 3, into chiral enamino ketones 4 (Scheme,1). Similarly, L -threonine 6 was transformed in four steps into the enamino ketone 10. Cyclocondensations of 4 and 10 with pyrazolamines 11, benzenecarboximidamide (12), and hydrazine derivatives 18 afforded N -protected 1-heteroaryl-2-phenylethanamines 15a,e, 16, 17, and 21a,k and 1-heteroaryl-1-aminopropan-2-ols 23a,b in good yields (Schemes,2 and 3). Finally, deprotection by catalytic hydrogenation furnished free amines 22a,g and 24a,b (Scheme,3). [source] Pyrazole Synthesis Using a Titanium-Catalyzed Multicomponent Coupling Reaction and Synthesis of WithasomnineADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 11-12 2009Supriyo Majumder Abstract The titanium-catalyzed 3-component coupling of an alkyne, isonitrile, and amine can be used to generate tautomers of 1,3-diimines. These diimines produced in situ undergo cyclization with hydrazine and hydrazine derivatives in a one-pot procedure to provide pyrazoles. Seventeen examples of pyrazoles are provided using this one-pot, 4-component procedure from simple starting materials. The regioselectivity of the alkyne addition can be controlled in some cases with catalyst architecture, and regioselectivity of monosubsituted hydrazines to unsymmetrical 1,3-diimines is discussed. This multicomponent coupling strategy was applied to the synthesis of withasomnine in an efficient procedure, which gave the natural product in 24% overall yield from 4-pentyn-1-ol. [source] Synthesis of pyridazine derivatives through the unexpected intermediate 5-amino- 4-cyano -2,3-dihydro-furan-2,3-disulfonic acid disodium saltJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 6 2003Barbara Cacciari An unexpected compound (5-amino-4-cyano-2,3-dihydrofuran-2,3-disulfonic acid disodium salt, 4) was isolated from the reaction of glyoxale bis hydrogen sulfite disodium salt with malononitrile. Its structure was undoubtly identified through crystal structure analysis. Compound 4 was highly stable and it was isolated easily and in a very high yield. Its reactivity was studied in the reactions with some hydrazine derivatives in order to obtain different pyridazine analogs. [source] | ||||||||||