• 제목/요약/키워드: natural reaction

검색결과 1,743건 처리시간 0.026초

Expeditious Synthesis of Natural Benzofuran, Eupomatenoid-6 by Umpolung of α-Aminophosphonates

  • Damodar, Kongara;Jun, Jong-Gab
    • Bulletin of the Korean Chemical Society
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    • 제35권12호
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    • pp.3618-3622
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    • 2014
  • Simple and practical synthesis of natural benzofuran derivative eupomatenoid-6 via Horner-Emmons type condensation as the key step is described. The umpolung property of aldehyde derivative, ${\alpha}$-aminophosphonate was efficiently employed in this reaction. ${\alpha}$-Aminophosphonate of anisaldehyde subjected to Horner-Emmons type condensation with 5-bromo-2-methoxybenzaldehyde to yield the deoxybenzoin, which was further methylated and then underwent tandem demethylation-cyclodehydration to afford the benzofuran scaffold in excellent yield. Finally Suzuki coupling with propenyl boronic acid afforded eupomatenoid-6 with an overall yield of 56.8%.

천연 Zeollte로부터 열수합성에 의한 주상 Na-P Zeolite합성 (Synthesis of Columnar Na-P Zeolite by Hydrothermal Process from Natural Zeolite of Korea)

  • 장용선;정필균;김상효
    • 한국토양비료학회지
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    • 제36권6호
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    • pp.357-366
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    • 2003
  • 본 연구는 천연 zeolite를 파쇄하여 일정크기의 입제를 생산하는 과정에서 부산물로 생산되는 다량의 미분을 이용하여 양이온치환용량이 높은 입상의 흡착제를 개발할 목적으로 수행하였다. 천연 zeolite를 알카리 용액의 열수합성법을 활용하여 Na-P zeolite로 전환시켰다. 반응시간별 합성과정 중 광물학적 특성 변화를 X-선회절, 주사전자현미경, 화학조성 및 CEC의 변화를 통하여 구명하였다. 주상 Na-P zeolite의 입단은 천연 zeolite-숯혼합물을 약 3 mm 두께로 압축성형한 후 열처리하였으며, 연속적인 3 M NaOH 처리로 천연 zeolite의 주요구성광물인 climoptile, moderite, 장석 등의 광물이 파괴되고 새로이 구형의 Na-P zeolite가 24시간 처리에서 관찰되었다. 반응시간이 증가함에 따라 잔류용액 중 Si/AI비는 감소하였으며, 입단 크기의 증가에도 불구하고 Na-P zeolite의 CEC는 출발물질로 사용된 미분의 천연 zeolite에 비하여 2배 이상 증가하였다.

Microwave Radiation-Assisted Chitin Deacetylation: Optimization by Response Surface Methodology (RSM)

  • Iqmal Tahir;Karna Wijaya;Mudasir;Dita Krismayanti;Aldino Javier Saviola;Roswanira Abdul Wahab;Amalia Kurnia Amin;Wahyu Dita Saputri;Remi Ayu Pratika
    • 한국재료학회지
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    • 제34권2호
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    • pp.85-94
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    • 2024
  • The optimization of deacetylation process parameters for producing chitosan from isolated chitin shrimp shell waste was investigated using response surface methodology with central composite design (RSM-CCD). Three independent variables viz, NaOH concentration (X1), radiation power (X2), and reaction time (X3) were examined to determine their respective effects on the degree of deacetylation (DD). The DD of chitosan was also calculated using the baseline approach of the Fourier Transform Infrared (FTIR) spectra of the yields. RSM-CCD analysis showed that the optimal chitosan DD value of 96.45 % was obtained at an optimized condition of 63.41 % (w/v) NaOH concentration, 227.28 W radiation power, and 3.34 min deacetylation reaction. The DD was strongly controlled by NaOH concentration, irradiation power, and reaction duration. The coefficients of correlation were 0.257, 0.680, and 0.390, respectively. Because the procedure used microwave radiation absorption, radiation power had a substantial correlation of 0.600~0.800 compared to the two low variables, which were 0.200~0.400. This independently predicted robust quadratic model interaction has been validated for predicting the DD of chitin.