• 제목/요약/키워드: Alkylation reaction

검색결과 87건 처리시간 0.023초

제올라이트 촉매상에서 1-Dodecene을 이용한 벤젠의 알킬화 반응 (Alkylation of Benzene over Zeolites with 1-Dodecene)

  • 신흥선;이동규
    • 한국응용과학기술학회지
    • /
    • 제16권2호
    • /
    • pp.117-125
    • /
    • 1999
  • The alkylation benzene with 1-dodecene of Mordenite, Zeolite ${\beta}$ and Zeolite Y was studied in the stirring batch reactor. The kinds of zeolites were found to have influenced the reaction conversion and distribution of phenyldodecane isomer in the product. Compared to the alkylation conducted over Zeolite Y and Zeolite ${\beta}$, the alkylation over Mordenite exhibited higher distribution of 2-phenyldodecane and the alkylation conducted over Zeolite Y and Mordenite, the alkylation over Zeolite ${\beta}$ exhibited higher distribution of heavy alkylate which formed through oligomerization reaction readily deactivated the Lewis acid sites. A special feature of the effect of the benzene to 1-dodecene ratio the reaction conversion and selectivity of phenyldodecane isomer was found. At alkylation of benzene with 1-dodecene over Zeolite ${\beta}$, when the catalyst content in the system was high, the reaction will reach the optimal conversion at the higher B/D. When the benzene to 1-dodecene ratio was high, the selectivity of phenyldodecane isomer is high. It was also found that at the similar reaction conversion there was the same product distribution regardless of D/C ratio.

A Theoretical Study on the N-Alkylation of a Pyrimidine with a Cyclopropa[c]inden-5-one; A Model Pharmacophore of Duocarmycins and CC-1065

  • Nahm, Kee-Pyung
    • Bulletin of the Korean Chemical Society
    • /
    • 제25권1호
    • /
    • pp.69-72
    • /
    • 2004
  • The N-alkylation of 4-aminopyrimidine with a tetrahydro-3-aza-cyclopropa[c]inden-5-one, which is a model reaction of the pharmacophore of duocarmycins, was studied with a quantum chemical method. We consider two factors for the acceleration of the N-alkylation; distortion and protonation of the model pharmacophores. The distortion of the spirocyclopropyl moiety in the model spirocyclopropylcyclohexadienone could induce an intrinsic energy of 3-4 kcal/mol, but the protonation on the carbonyl oxygen of the model cyclohexadienone lowers the transition energy of the N-alkylation of 4-aminopyrimidine dramatically (~46 kcal/mol) and is considered to play a major role in the enzyme reaction. The distorted and protonated spirocyclohexadienone is exothermally relieved to a phenol with the heat of reaction of -37 kcal/mol. The protonation process is proposed to be the mode of action of duocarmycins in the DNA alkylation.

이온성액체를 이용한 이소부탄 알킬레이션 반응성능에 대한 예측 (Prediction of Reaction Performance of Isobutane Alkylation Using Ionic Liquid)

  • 김수정;유계상
    • 공업화학
    • /
    • 제26권3호
    • /
    • pp.347-350
    • /
    • 2015
  • 본 논문에서는 친환경 촉매 중 하나인 이온성액체를 이용한 이소부탄 알킬레이션 반응에 대해서 연구하였다. 산성 이온성액체 중 하나인 1-Octyl-3-methylimidazolium-bromide-aluminum chloride를 촉매로 사용하였다. 최적의 반응조건을 규명하기 위하여 액체공간속도, 반응온도 및 이온성액체의 조성에 따른 반응성능에 대하여 조사하였다. 일정한 실험 조건에서 반응온도의 경우 $80^{\circ}C$에서 최적의 반응성능을 보였고 이온성액체의 조성은 음이온 비가 0.56인 경우 우수한 반응특성을 보였다. 또한 반응조건에 따른 생성물의 수율을 예측할 수 있는 모델식을 통계학적 접근을 통해 완성하였다.

A Theoretical Study on the Alkylation of the Ambident Enolate from a Methyl Glycinate Schiff Base

  • Nahm, Kee-Pyung;Lee, Seung-Min
    • Bulletin of the Korean Chemical Society
    • /
    • 제33권8호
    • /
    • pp.2711-2718
    • /
    • 2012
  • The alkylation of the ambident enolates of a methyl glycinate Schiff base with ethyl chloride was studied at B3LYP and MP2 levels with $6-31+G^*$ basis set. The free (E)-enolates and (Z)-enolate are similar in energy and geometry. The transition states for the alkylation of the free (E)/(Z)-enolate with ethyl chloride have similar energy barriers of ~13 kcal/mol. However, with a lithium ion, the (E)-enolate behaves as an ambident enolate and makes a cyclic lithium-complex in bidentate pattern which is more stable by 11-23 kcal/mol than the (Z)-enolate-lithium complexes. And the TS for the alkylation of (E)-enolate-lithium complex coordinated with one methyl ether is lower in energy than those from (Z)-enolate-lithium complexes by 4.3-7.3 kcal/mol. Further solvation model (SCRF-CPCM) and reaction coordinate (IRC) were studied. This theoretical study suggests that the alkylation of ambident enolates proceeds with stable cyclic bidentate complexes in the presence of metal ion and solvent.

Synthesis of (2,7-dibromo-9,9-dialkyl-substituted-fluorene)s for Poly(dialkylfluorene)s by Phase Transfer Catalytic Reaction

  • Kwon, Seung-Ho;Kim, Jin-Sung;Park, Ji-Ho;Yoo, Jae-Soo
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 한국정보디스플레이학회 2002년도 International Meeting on Information Display
    • /
    • pp.724-727
    • /
    • 2002
  • 2,7-dibromo-9, 9-dialkyl-substituted-fluorene derivatives were prepared by the alkylation of 2,7-dibromofluorene with various alkyl groups under two-phase phase transfer catalysis (PTC) conditions, as monomers for synthesizing poly(dialkylfluorene)s. Tetra-nbutylammonium hydrogen sulfate (TBAHS) was used as a phase transfer catalyst to enhance nucleophilic substitution. In addition, NaOH in water (25M) was used as a base to generate anions. Compared to conventional alkylation using butyllithium(BuLi), the reaction using the PTC technique attained high selectivity and substantial conversion of reactants, due to the enhanced reaction rate, while the reaction was carried out under moderate conditions. An approximately 90% yield was obtained from the reaction and the reaction time was remarkably reduced. 2,7-dibromo-9,9-dihexyl-fluorene, 2,7-dibromo-9,9-dioctyl-fluorene, and 2,7-dibromo-9,9-di(2-ethylhexyl)-fluorene were effectively synthesized by phase transfer catalytic reaction.

  • PDF

Synthesis and Preliminary Antimicrobial Screening of New Benzimidazole Heterocycle

  • Fahmy, H.H.;El-masry, A.;Ali Abdelsahed, S.H.
    • Archives of Pharmacal Research
    • /
    • 제24권1호
    • /
    • pp.27-34
    • /
    • 2001
  • A series of 2-methylbenzimidazole incorporated to different heterocycles through ethyl or carbamoylethyl groups at position 1 of benzimidazole were synthesized. Also 3-(2-methylbenzimidazol-1-yl)propanoic acid hydrazide incorporated with semicarbazides and thiosemicarbazides were prepared. Moreover, the triazole 5e underwent Michael addition and alkylation reaction. Some of the newly synthesized compounds showed considerable antimicrobial activity against gram positive, negative bacteria and yeast.

  • PDF