- Preparation method of 4- polyfluoro methoxy O-phenylenediamine (by machine translation)
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The method disclosed by the invention 4 - is characterized in that the aminophenol, and the alkali :(1) are reacted at a mole ratio of the 1:0.8-1.5, 20-40 °C compound 0.1-24h with the halogen, and, the halogen compound in the solvent to 1:1.0-3.0,20-120 °C, 0.01-20Mpa react with 1-72h. 1-72h the 4 - 1:0.8-30.0 ammonia solution ;(2)4 - or the halogen compound at a mole ratio of the compound of the 1:0.2 - 2.5 amino phenol, 30-80 °C with 0.1-24h;(3)4 - the halogen and the halogen compound in the solvent 0.1-10%, 50-200 °C, 0.01-10Mpa: 4 . (by machine translation)
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Paragraph 0013
(2020/01/03)
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- Triple Mode of Alkylation with Ethyl Bromodifluoroacetate: N, or O-Difluoromethylation, N-Ethylation and S-(ethoxycarbonyl)difluoromethylation
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In this report, we have explored a triple mode of chemical reactivity of ethyl bromodifluoroacetate. Typically, bromodifluoroacetic acid has been used as a difluorocarbene precursor for difluoromethylation of soft nucleophiles. Here we have disclosed nucleophilicity and base dependent divergent chemical reactivity of ethyl bromodifluoroacetate. It furnishes lithium hydroxide and cesium carbonate promoted difluoromethylation of tosyl-protected aniline and electron-deficient phenols respectively. Interestingly, switching the base from lithium hydroxide to 4-N,N-dimethylamino pyridine (DMAP) tosyl-protected anilines afforded the corresponding N-ethylation product. Whereas, highly nucleophilic thiophenols furnished the corresponding S-carboethoxydifluoromethylation product via a rapid SN2 attack to the bromine atom prior to the ester hydrolysis. This mechanistic divergence was established through several control experiments. It was revealed that difluoromethylation reaction proceeds through a tandem in situ ester hydrolysis/decarboxylative-debrominative difluorocarbene formation and subsequent trapping by the soft nucleophile-NHTs or electron-deficient phenolic ?OH groups. In the presence of DMAP the hydrolysis of the ester is perturbed instead a nucleophilic attack at the ethyl moiety provides the N-ethylation product. Hence, besides the development of a practical base-promoted N-difluoromethylation of amines and electron-deficient phenols, divergent reactivity pattern of inexpensive and user-friendly ethyl bromodifluoroacetate has been explored. (Figure presented.).
- Polley, Arghya,Bairy, Gurupada,Das, Pritha,Jana, Ranjan
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supporting information
p. 4161 - 4167
(2018/09/21)
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- Diversified synthesis of novel quinoline and dibenzo thiazepine derivatives using known active intermediates
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The novel drug development to control resisting infections in conventional drug therapy is a need of today. Few antiulcer relative derivatives developed by approaching convergent synthesis. The derivatives synthesized successfully are dibenzo thiazepine-pyridine (SLN11-SLN15) and benzimidazole-hydroquinoline based derivatives (SLN16-SLN20). It involved the coupling through microwave, sonication and conventional techniques at final step. The efficient technology identified as sonication technique basically time and yield. The reported compounds were structural characterized by elemental analysis and spectral studies such as 1H, 13C NMR and MS.
- Sharada,Satyanarayana Reddy,Sammaiah,Sumalatha
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p. 7959 - 7966
(2013/09/23)
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