Studies of the Absorption Spectra of Azo Dyes and their Metal-complexes. II. The Absorption Spectra of Phenolazoacetoacetamide and its Derivatives
作者:Yoshiharu Yagi
DOI:10.1246/bcsj.36.492
日期:1963.5
phenolic nucleus and a hydrazone group, and the D bands, in a conjugative electronic transition between a carboxylic acid anilide group and a hydrazone group. From the investigation of the series of spectra in phenolazoacetoacetbenzylamides, the B bands have been assigned to the conjugation band; they arise from a conjugative electronic transition within a partial chromophore consisting of an acetyl carbonyl
酚偶氮乙酰乙酰胺呈腙形式。酚羟基在固态和非极性溶剂中与腙氮原子形成分子内氢键。这些化合物的电子吸收光谱表现出四组特征谱带: A 谱带产生于涉及电子沿相应化合物整个共轭体系迁移的跃迁;C 带起源于酚核和腙基团之间的共轭电子跃迁,D 带起源于羧酸酰苯胺基团和腙基团之间的共轭电子跃迁。从对苯酚偶氮乙酰乙酰苄基酰胺的系列光谱的研究来看,B 带已被指定为共轭带;
Synthesis of substituted dihydro-1H-pyrazoles and 1H-pyrazoles via formal [4+1] annulation of α-arylhydrazonoketones and dimethyl sulfonium methylides
formal [4+1] annulation of readily available α-arylhydrazonoketones and dimethyl sulfonium methylides is described, which involving tandem ylide-mediated addition and nucleophilic cyclization reactions. This transformation features mild reaction conditions, simple execution, good to high yields, and provides straightforward synthesis of substituted dihydro-1H-pyrazoles and 1H-pyrazoles via C-C and
A formal [4 + 1] annulation of readily available α-arylhydrazonoketones and trimethylsulfoxonium iodide in the presence of cesium carbonate is described involving a sequential Corey–Chaykovsky reaction and intramolecular nucleophilic cyclization process. Substituted pyrazoles were obtained exclusively from the reactions of α-arylhydrazono-β-oxo-amides and trimethylsulfoxonium iodide in moderate to
Base-induced cyclocondensation of acetoacetanilide (1) and benzoyl isothiocyanate (2) afforded mercaptopyridine (4). Compound 4 reacted with NaOCl in presence of NH4OH/NaOH to produce isothiazolopyridine (6). Heterocyclization of 4 by ethyl bromoacetate and/or phenacyl bromide afforded pyridothiazapene and pyridine derivatives 7, 8, respectively. The synthesis of pyrazolopyridine (9) was achieved by reaction of 4 with hydrazine hydrate. Oxidative cyclization of 4 by Br2 produced isothiazolopyridine (10). Chlorination of compound 4 yielded isothiazolopyridine dioxide (11). Compound 1 transformed into pyrane derivatives 12 and 13 by reaction with benzylidenemalononitrile and benzylideneacetophenone, respectively. Heterocyclization of compound 1 by ethylcyanoacetate and diethyloxalate afforded pyridine and cyclopentane derivatives 14 and 15, respectively. Compound 1 heterocyclized to indenopyrane (16) or indenopyrrole (17) upon reacted with ninhydrin on cold and hot condition, respectively. Heterocyclization of compound 1 and benzilmonohydrazone afforded pyridazine derivative 18. Coupling of 1 with diazonium salt afforded hydrazone 19 which cyclized using CS2/KOH gave pyridazine derivative 20.
Kinetics and mechanism of gas-phase pyrolysis ofN-aryl-3-oxobutanamide ketoanilides, their 2-arylhydrazono derivatives, and related compounds
作者:Rana N. Malhas、Nouria A. Al-Awadi、Osman M. E. El-Dusouqui
DOI:10.1002/kin.20220
日期:2007.2
Rates and products of reaction and Arrhenius activation parameters were determined for the gas-phase thermolysis of 14 substrates of the title compounds using sealed pyrex reactor tubes and HPLC/UV-VIS to monitor substrate pyrolysis. The 14 compounds under study are N-phenyl-3-oxo- (1), N-(p-chlorophenyl)-3-oxo- (2), N-(p-methylphenyl)-3-oxo- (3), and N-(p-methoxyphenyl)-3-oxobutanamide (4), in addition