The first route involved the synthesis of 2-acetylbenzofuran and then treatment with aldehydes to afford the corresponding chalcones. The cyclization of the latter chalcones with hydrazine hydrate led to the formation of new pyrazoline derivatives. The second route involved the synthesis of benzofuran...
PALACIOS, F.; OCHOA DE RETANA, A.M.; PAGALDAY, J.; A Regioselective Synthesis of 5-Pyrazolones and Pyrazoles from Phosphazenes derived from Hydrazines and Acetylenic Esters. Thetrahedron, Espanha, v. 55, n. 50, p. 14451-14458, 1999....
[37] and Mosby [38] respectively, whereas the linkers H2Me4BDP and H2Me4BDPB were prepared following the synthesis reported by Li and co-workers [39], based on the condensation of the pertinent bis(diketone) with hydrazine hydrate in aqueous medium. These methyl-functionalized linkers were ...
Synthesis and crystal structure of (±)-Ethyl 5′-(difluoromethyl)-2-oxo-4′,5′-dihydrospiro[indoline-3,3′-pyrazole]-4′-carboxylate, C14H13F2N3O3 Wu-Wu Li , Min-Yan Zheng , Ying Guo , Yan-Ping Jiang , Qiao Wang , Mei Wang , Min-Xiang Ji , Yu-Tao Zhang and Zun-Ting Zhang...
As to the amount of the reagent used for the reaction, the amount of hydroxylamine, hydrazine or a mineral acid (e.g. hydrochloric acid, sulfuric acid) is from 0.5 to 100 moles per 1 mole of the compound of the formula (XIII). The reaction temperature is usually from 0° to 300° ...
Rapid synthesis of tetrahydro-4H-pyrazolo[1,5-a]diazepine-2-carboxylate Hydrazines condense with dimethyl 2-pyrrolidino-4-oxo-2-pentenedioate in the presence of aq. HCl to form N-substituted pyrazole-3,5-dicarboxylates 2. Compl... Raymond J. Cvetovich and Brenda Pipik and Frederick W. Ha...
The molecules 5--1--1H--4-(3a-f) were synthesized from (ethoxymethylene)malo-nonitrile (1) and fluorinated and non-fluorinated aryl hydrazines (2a-f) using ethanol and fluorinated ethanol as solvents at reflux. An excellent regio-selectivity was found when pyrazole derivatives were formed as...
The use of solid-phase-supported synthesis methods permits a series of protocols which are known from the literature and which, in turn, can be performed manually or in an automated manner. For example, the “tea-bag method” (Houghten, U.S. Pat. No. 4,631,211; Houghten et al., Proc...
Reaction of ketene derivatives (1a,b) on treatment with 4-amino-1-phenyl-2,3-dimethyl pyrazolin-5-one gives compounds (2a,b) which react with hydrazine to ... EMM Kassem,SE Difrawy,OA Fathalla,... 被引量: 0发表: 1993年 Synthesis of 7-substituted-4-(3',4',5'-trisubstituted-1-...
The synthesis of a new series of hydroxypyrazoles () and 2-methyl-3-isoxazolones () from the cyclocondensation reaction of trichloromethyl-substituted 1,3-dielectrophiles () with dry hydrazine and-methylhydroxylamine is reported. The regiospecific cyclocondensation took place with the elimination of...