• 제목/요약/키워드: Aromatization

검색결과 27건 처리시간 0.028초

Propylene Aromatization에 미치는 온도 및 촉매의 영향 (Effect of Temperature on Propylene Aromatization over MFI Type Zeolites)

  • 박진우;김상범;곽윤철;신기석;박홍수;함현식
    • 한국응용과학기술학회지
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    • 제19권2호
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    • pp.123-130
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    • 2002
  • [Ga]-MFI and H-ZSM-5 catalysts were synthesized under atmospheric pressure and used in the propylene aromatization. The effect of temperature on the product distribution was also investigated. The catalytic activities of the prepared catalysts were compared with the commercialized H-ZSM-5 which was converted from $NH_{4}$-ZSM-5. In the propylene aromatization, product distribution does not depend on the ratio of Si/$Ga_{2}$ with [Ga]-MFI catalyst, but depend on the ratio of Si/$Al_{2}$ with H-ZSM-5 catalyst [Ga]-MFI catalyst shows better dehydrogenation and alkylation activities than H-ZSM-5 catalyst The addition of Ga to H-ZSM-5 catalyst increases the conversion of propylene, selectivity to aromatics, and alkylation. In the propylene aromatization, the selectivity to aromatics slightly increased with increasing temperature with [Ga]-MFI catalyst, while slightly decreased with increasing temperature with H-ZSM-5 catalyst.

An Expeditious Oxidative Aromatization of Hantzsch 1,4-Dihydropyridines to Pyridines Using Cetyltrimethylammonium Peroxodisulfate: A Phase Transferring Oxidant

  • Kumar, Parvin;Kumar, Ashwani
    • Bulletin of the Korean Chemical Society
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    • 제31권8호
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    • pp.2299-2303
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    • 2010
  • A new approach to the use of potassium peroxodisulphate as an oxidizing reagent is proposed and applied to the case of oxidative aromatization of 1, 4-dihydropyridines with cetyltrimethylammonium peroxodisulfate, a phase transfer oxidant. We demonstrate how it is possible to increase the reactivity of potassium peroxodisulphate in the presence of phase transfer catalyst. Dealkylation in case of 4-n-alkyl/n-alkenyl was not obtained.

Chemistry of the 3a,7a-Dihydro-1H-indole Esters. Aromatization by Bromine$^\dag$

  • Lee, Chang-Kiu;Ahn, Yu-Mi;Han Lee, In-Sook
    • Bulletin of the Korean Chemical Society
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    • 제7권4호
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    • pp.311-314
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    • 1986
  • A series of tetramethyl 1-substituted benzyl-3a,7a-dihydro-1H-indole-2,3,3a,4-tetracarboxylates were prepared and their reactions with bromine were examined. The initial reaction seemed to be the formation of the intermediate N-bromo quaternary ammonium bromide. This intermediate underwent aromatization with loss of the 3a-methoxycarbonyl group. Bromine replaced the N-substituent of the p-methoxybenzyl compound and addition of bromine occurred across the $C_6-C_7$ double bond of the indole ring. Bromination of the benzyl ring and aromatization occurred for the m-methoxybenzyl compound.

지오라이트 촉매를 이용한 메탄의 활성화 반응에서 일산화탄소/이산화탄소 첨가에 따른 영향 (Effects of $CO/CO_{2}$ Additives on The Reaction of Methane Activation using The Zeolite Catalyst)

  • 정귀영
    • 한국응용과학기술학회지
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    • 제17권2호
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    • pp.139-143
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    • 2000
  • There appeared enhancements of the conversion of methane by adding a small amount of CO in the aromatization reaction of methane using the Mo-zeolite catalyst. In case of adding $CO_{2}$, $CO_{2}$ changed to CO first, and then the conversion reaction occurred. It was observed by using isotopes as reactants that CO is related to the aromatization reaction of methane.

Aromatization of 1,3,5-Trisubstituted of 4,5-Dihydro-1H-Pyrazoles by In-Situ Generation of I+ from Hydrogen Peroxide/Acids/Iodide Potassium or Sodium Systems

  • Maleki, Behrooz;Veisi, Hojat
    • Bulletin of the Korean Chemical Society
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    • 제32권12호
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    • pp.4366-4370
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    • 2011
  • A simple, green and cost-effective protocol was used for the aromatization of 1,3,5-trisubstituted-2-pyrazolines to the corresponding pyrazoles by in situ generation of iodine ($I^+$) from $H_2O_2$/AcOH or SSA or oxalic acid /KI or NaI system under thermal condition with moderate to good yields.