137-04-2Relevant articles and documents
Steric hindrance as a key factor on proton transfer in the σ-adduct forming reactions of o-substituted anilines with 1,3,5-trinitrobenzene in dimethylsulfoxide
Asghar, Basim H.
, p. 1191 - 1195 (2008)
Kinetic and equilibrium studies are reported of the reactions of 1,3,5-trinitrobenzene (TNB) with a series of o-substituted anilines in dimethyl sulfoxide (DMSO) in the presence of 1,4-diazabicyclo[2.2.2.]octane (DABCO). The pKa values in DMSO for the aniline derivatives were measured using the proton-transfer equilibrium with 2,4-dinitrophenol. Kinetic studies are compatible with a two-step process involving initial nucleophilic attack on TNB by amine to give a zwitterionic intermediate which may transfer an acidic proton to DABCO to yield the anionic product. The results indicate steric hindrance to proton transfer in reactions involving 2,6-disubstituted anilines.
Synthesis of 7-halo indoles (by machine translation)
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Paragraph 0021, (2017/01/12)
The present invention relates to synthesis of 7? Halo indole method, comprising the steps of:O-halogenated aniline, chloral hydrate and hydroxylamine hydrochloride by the Sandmeyer reaction to synthesize 7? halogenating isatin ; 7? halogenating isatin dissolved with an organic solvent, in the reducing agent by reduction reaction under the conditions of 7? Halo indole, the reducing agent is an alkali metal borohydride system, four system adopts, lithium hydride system or triethyl silane system. The beneficial effect of the invention is:in order to O-halogenated aniline and the chloral hydrate is, hydroxylamine hydrochloride as raw materials, by the Sandmeyer shall synthesis method for preparing compositions b isonitroso 7? halogenating isatin, and then by further reduction and system reduction to prepare 7? Halo indole; by the 7? Preparation halogenating isatin 7? Halo indole method, the raw material is easy to obtain, low price, higher process yield, the product purity is good, simple operation, and the like, is suitable for batch preparation 7? Halo indole. (by machine translation)
The ortho effect on the acidic and alkaline hydrolysis of substituted formanilides
Desai, Salil Dileep,Kirsch, Lee E.
, p. 471 - 488 (2015/06/30)
The kinetics of formanilides hydrolysis were determined under first-order conditions in hydrochloric acid (0.01-8 M, 20-60°C) and in hydroxide solutions (0.01-3 M, 25 and 40°C). Under acidic conditions, second-order specific acid catalytic constants were used to construct Hammett plots. The ortho effect was analyzed using the Fujita-Nishioka method. In alkaline solutions, hydrolysis displayed both first- and second-order dependence in the hydroxide concentration. The specific base catalytic constants were used to construct Hammett plots. Ortho effects were evaluated for the first-order dependence on the hydroxide concentration. Formanilide hydrolyzes in acidic solutions by specific acid catalysis, and the kinetic study results were consistent with the AAC2 mechanism. Ortho substitution led to a decrease in the rates of reaction due to steric inhibition of resonance, retardation due to steric bulk, and through space interactions. The primary hydrolytic pathway in alkaline solutions was consistent with a modified BAC2 mechanism. The Hammett plots for hydrolysis of meta- and para-substituted formanilides in 0.10 M sodium hydroxide solutions did not show substituent effects; however, ortho substitution led to a decrease in rate constants proportional to the steric bulk of the substituent.
