• 제목/요약/키워드: Nitriles

검색결과 82건 처리시간 0.026초

Transformation of Carboxylic Acids and Their Derivatives into Aldehydes by Lithium Tris(dialkylamino)aluminum Hydrides

  • Cha Jin Soon
    • Bulletin of the Korean Chemical Society
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    • 제13권6호
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    • pp.670-676
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    • 1992

  • A systematic study of the partial reduction of carboxylic acids and their derivatives to the corresponding aldehydes with lithium tris(dialkylamino)aluminum hydrides under practical conditions has been carried out. The diethylaminosubstituted derivative of lithium aluminum hydride, lithium tris(diethylamino)aluminum hydride (LTDEA), shows quite general applicability in the conversion of carboxylic acids, carboxylic esters, and primary carboxamides to the corresponding aldehydes. Lithium tripiperidinoaluminum hydride (LTPDA) also appears to be a reagent of choice for such partial transformation of primary carboxamides. In additioin, both LTDEA and LTPDA reduce tertiary carboxyamides to aldehydes in high yields. Finally, lithium tris(dihexylamino)aluminum hydride (LTDHA) is capable of achieving the chemoselective reduction of aromatic nitriles to aldehydes in the presence of aliphatic nitriles under practical conditions.

  • https://doi.org/10.5012/bkcs.1992.13.6.670 인용 PDF

Reactions with Activated Nitriles : A new route for the synthesis of new pyridine and pyrazolopyridine derivatives

  • Attaby, Fawzy-A.;Eldin, Sanaa-M.
    • Archives of Pharmacal Research
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    • 제13권3호
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    • pp.274-277
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    • 1990

  • It has been found that $\alpha, \beta$-unsaturated nitrile derivatives 1-3 reached with S- methylisothiourea to give the prpone derivatives 4-6 respectively. Cyclisation of 4-6 using ethanolic hydrochloric acid afforded the pyridine derivatives 7-9 in good yields. On the other hand, the reactions of hydrazine hydrate and of phenylhydrazine with each of 7-9 gave the corresponding pyrazolopyridine derivatives 10-15. The structures of the newly synthesised derivatives were assigned on the basis of elemental analyses, IR and $^1H$-NMR spectral data studies.

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Raction of Thexylbromoborane-Methyl Sulfide in Methylene Chloride with Selected Organic Compounds Containing Representative Functional Groups$^\dag$

  • Cha, Jin-Soon;Kim, Jin-Euog;Oh, Se-Yeon
    • Bulletin of the Korean Chemical Society
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    • 제8권4호
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    • pp.313-318
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    • 1987

  • The approximate rate and stoichiometry of the reaction of excess Thexylbromoborane-methyl sulfide, $ThxBHBr{\cdot}SMe_2,$ with selected organic compounds containing representative functional groups under standardized conditions (methylene chloride, $0^{\circ}C)$ were studied in order to characterize the reducing characteristics of the reagent for selective reductions. The selectivity of the reagent was also compared to the selectivity of thexylchloroborane-methyl sulfide. Thexylbromoborane appears to be a much milder and hence more selective reducing agent than thexylchloroborane. The reagent tolerates many organic functionalities. Thus, the reagent shows very little reactivity or no reactivity toward acid chlorides, esters, epoxides, amides, nitro compounds including simple olefins. However, this reagent can reduce aldehydes, ketones, carboxylic acids, nitriles, and sulfoxides. Especially the reagent reduces carboxylic acids including ${\alpha},{\beta}$ -unsaturated ones and nitriles to the corresponding aldehydes. In addition to that, thexylbromoborane shows good stereoselectivity toward cyclic ketones, much better than the chloro-derivative.

  • https://doi.org/10.5012/bkcs.1987.8.4.313 인용 PDF