• Title/Summary/Keyword: Aromatic Aldehydes

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Solid-Phase Synthesis of 2-Arylbenzothiazole Using Silica Sulfuric Acid under Microwave Irradiation

  • Niralwad, Kirti S.;Shingate, Bapurao B.;Shingare, Murlidhar S.
    • Bulletin of the Korean Chemical Society
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    • v.31 no.4
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    • pp.981-983
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    • 2010
  • The condensation of several aromatic/heteroaromatic aldehydes with 2-aminothiophenol catalyzed by silica sulfuric acid under microwave irradiation afforded 2-arylbenzothiazoles in high yields and short reaction times under solvent-free conditions. The major advantages of the present method are good yields, ecofriendly, reusable catalyst, mild and solvent-free reaction conditions.

Catecholalane (1,3,2-Benzodioxaluminole) as a Selective Reducing Agent

  • 차진순;장석원;이지은;김종미;권오운;이형수;송한철
    • Bulletin of the Korean Chemical Society
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    • v.17 no.8
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    • pp.720-724
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    • 1996
  • Catecholalane (1,3,2-Benzodioxaluminole, CA) prepared from catechol and aluminum hydride in tetrahydrofuran (THF) is found to be a selective reducing agent. The systematic study in order to characterize the reducing properties of the reagent under practical conditions (THF, 0 or 25 ℃, the quantitative amount of reagent to compound) has been done. The reagent reduces aldehydes, ketones, esters and acid chlorides to the corresponding alcohols, and primary amides to the corresponding amines. Especially noteworthy is that the reagent can convert both aromatic and aliphatic nitriles to the corresponding aldehydes in very high yields.

Analysis of Volatile Flavor Components from Allium senescens (두메부추의 휘발성 향기성분 분석)

  • 이미순;정미숙
    • Korean journal of food and cookery science
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    • v.17 no.1
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    • pp.55-59
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    • 2001
  • To investigate the usefulness of Allium senescens as a aromatic edible plant, volatile flavor components and flavor pattern were analyzed. Essential oils of fresh and freeze dried Allium senescens were extracted by SDE(simultaneous steam distillation and extraction) method using diethyl ether as solvent. And their volatile flavor components were analyzed by gas chromatography(GC) and gas chromatography-mass spectrometry (GC-MS). A total of 46 components, including 11 hydrocarbons, 9 aldehydes, 4 alcohols, 2 esters, 7 acids, 4 ketones and 9 sulfur containing compounds were identified in fresh Allium senescens. In freeze dried Allium senescens, 8 hydrocarbons, 5 aldehydes, 3 alcohols, 5 esters, 2 acids, 3 ketones and 4 sulfur containing compounds were identified. Volatile flavor patterns of Chinese chive and Allium senescens were compared using electronic nose. The score of first principal component was significantly different in Allium senescens and Chinese chive.

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Reaction of Dipyrrolidinoaluminum Hydride in Tetrahydrofuran with Selected Organic Compounds Containing Representative Functional Groups

  • Jin Soon Cha;Oh Oun Kwon;Jong Mi Kim;Jae Cheol Lee
    • Bulletin of the Korean Chemical Society
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    • v.15 no.8
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    • pp.644-649
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    • 1994
  • The approximate rates and stoichiometry of reaction of excess dipyrrolinoaluminum hydride (DPAH) with selected organic compounds containing representative functional groups under standardized conditions (tetrahydrofuran, 0, reagent : compound=4 : 1) were examined in order to define the characteristics of the reagent for selective reductions. The reducing ability of DPAH was also compared with that of bis(diethylamino)aluminum hydride (BEAH). The reagent appears to be stronger than BEAH, but weaker than the parent reagent in reducing strength. DPAH shows a unique reducing characteristics. Thus, the reagent reduces aldehydes, ketones, esters, acid chlorides, epoxides, and nitriles readily. In addition to that, ${\alpha},\;{\beta}$-unsaturated aldehyde is reduced to the saturated alcohol. Quinone are reduced cleanly to the corresponding 1,4-reduction products. The examination for possibility of achieving a partial reduction to aldehydes was also performed. Both primary and tertiary aromatic carboxamides are converted to aldehydes with a limiting amount of DPAH. Finally, disulfides and sulfoxides are readily reduced to thiols and sulfides, respectively.

Changes of Volatile Flavor Compounds in Low-Salt-Fermented Anchovy Paste by Adding Koji (Koji를 이용한 멸치젓 숙성중 휘발성 향기성분의 변화에 관한 연구)

  • Yong-Jun Cha
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.23 no.3
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    • pp.481-489
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    • 1994
  • Volatile flavor compounds in low salt-fermented anchovy pastes by adding koji(Koji), compared with Control, were analyzed by simultaneous steam distillation -solvent extraction /gas chromatography/mass spectrometry. Volatile compounds (106) were detected inboth samples during fermentation. Among these, 79 compounds were positively identified and were composed mainly of aldehydes, esters, alcohols, ketones, nitrogen-containing compounds, aromatic hydrocarbons, and furans. Aldehydes and esters were found higher amounts that other compounds in both samples. Alkylpyrazine, such as 2, 6-dimethylpyrzine, 2-ethyl-6-methylpyrazine, trimethylpyrazie, 2-ethyl-3, 5-dimethylpyrazine and tetramethylpyrazine, and also 2-phenylethanol were identified only in Koji.

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