• 제목/요약/키워드: Microwave synthesis

검색결과 235건 처리시간 0.02초

마이크로파 에너지에 의해 결정 크기가 조절된 유기 안료의 합성 (The Synthesis of Crystalline-Size Controlled Organic Pigment by Microwave Energy)

  • 정기석;고진필;박상보;박찬영;민성기;권종호;오인환;박성수
    • 폴리머
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    • 제25권5호
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    • pp.609-616
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    • 2001
  • 본 연구에서는 copper phthalocyanine (CUPc)을 높은 합성 수율로서 성공적으로 합성시킴에 따라 용매를 사용하는 고분자의 합성 분야에 마이크로파 기술의 응용 가능성을 제시하고자 하였다. 가정용 전자레인지의 용기를 개조시키고 마이크로파 출력 조절기를 부착시키는 방법으로 본 실험에 사용되는 가변식 마이크로파 합성 장치를 자체 제작하였다. 화학 분석법, X선 회절장치(XRD), 주사형 전자현미경 (SEM) 및 입도 분석법 (PSA)을 이용하여 재래식 열 공정 및 마이크로파 공정을 사용하여 여러 조건하에서 합성된 시료들의 특성을 비교 분석하였다.

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Synthesis and Characterization of Some Quinazoline Derivatives as Potential Antimicrobial Agents under Microwave Irradiation

  • Mehta, Sarika;Swarnkar, Neelam;Vyas, Madhuri;Vardia, Jitendra;Punjabi, Pinki B.;Ameta, Suresh C.
    • Bulletin of the Korean Chemical Society
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    • 제28권12호
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    • pp.2338-2343
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    • 2007
  • Under the framework of green chemistry, an efficient and extremely fast procedure for the synthesis of 5a-h through four-step procedure starting from 2-arylidenetetralin-1-one 1a-d under microwave irradiation is described. A considerable increase in the reaction rate has been observed with better yield. The structures of the synthesized compounds have been characterized on the basis of their elemental analysis and spectral data. Synthesized compounds 5a-h was evaluated for their antimicrobial activity. Some of the compounds exhibited appreciable activity.

가정용 전자렌지를 사용한 천연규석분말과 Al분말 성형체로부터 사이알론상 합성에 관한 연구 (The Sialon Synthesis from Natural Silica and Al Powder Mixture by Using Home-style Microwave Oven)

  • 안주삼
    • 한국세라믹학회지
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    • 제34권1호
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    • pp.1-6
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    • 1997
  • 가정용 전자 렌지를 사용하여, SiO2-Al 분말 성형체로 이루어진 시편을 질화분위기에서 점화시켰다. 연소파대가 전파되면서 미반응물없이 Si와 AIN와 Al2O3를 석출하였으며, 냉각과정을 거치지 않고 곧바로 석출물들이 마이크로파를 흡수하여 고온에서 가열되어서 사이알론상을 합성하였다. 전자렌지안에서 SiO2-Al 분말성형체로부터 사이알론상들의 합성율은 일반적인 로내에서의 합성율보다 높았고, 공정시간이 불과 1시간내외에 이어서 에너지와 제조경비를 절약할 수 있었다.

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A Facile Synthesis of SAPO-34 Molecular Sieves with Microwave Irradiation in Wide Reaction Conditions

  • Jun, Jong-Won;Lee, Ji-Sun;Seok, Hwi-Young;Chang, Jong-San;Hwang, Jin-Soo;Jhung, Sung-Hwa
    • Bulletin of the Korean Chemical Society
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    • 제32권6호
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    • pp.1957-1964
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    • 2011
  • Various reaction conditions uding temperature, time and type and concentration of templates have been changed in order to facilely synthesize, especially with microwave (MW) heating, SAPO-34 molecular sieves. SAPO-34 molecular sieve can be synthesized rapidly with microwave irradiation from a gel containing tetraethylammonium hydroxide (TEAOH) as a template. However, other several templating molecules lead to SAPO-5 molecular sieve under microwave irradiation even though SAPO-34 is obtained by conventional electric synthesis from the same reactant gels. Moreover, SAPO-34 can be obtained more easily by increasing the TEAOH or silica concentration or by increasing the reaction temperature. SAPO-34 can be obtained within 5 min in a selected condition (high temperature of 210 $^{\circ}C$) with microwave heating, which may lead to a continuous production of the important material. SAPO-34 synthesized by microwave irradiation is homogeneous and small in size and shows acidity and a stable performance in the dehydration of methanol and 2-butanol to olefins, suggesting potential applications in acid catalysis.

Effect of microwave irradiation on lipase-catalyzed reactions in ionic liquids

  • An, Gwangmin;Kim, Young Min;Koo, Yoon-Mo;Ha, Sung Ho
    • 분석과학
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    • 제30권3호
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    • pp.138-145
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    • 2017
  • Microwave-assisted organic synthesis has gained a remarkable interest over the past years because of its advantages - (i) rapid energy transfer and superheating, (ii) higher yield and rapid reaction, (iii) cleaner reactions. Ionic liquids are well known for their unique properties such as negligible vapor pressure and high thermal stability. With these properties, ionic liquids have gained increasing attention as green, multi-use reaction media. Recently, ionic liquids have been applied as reaction media for biocatalysis. Lipase-catalyzed reactions in ionic liquids provide high activity and yield compared to conventional organic solvents or solvent free system. Since polar molecules are generally good absorbent to microwave radiation, ionic liquids were investigated as reaction media to improve activity and productivity. In this study, therefore, the effect of microwave irradiation in ionic liquids was investigated on lipase catalyzed reactions such as benzyl acetate synthesis and caffeic acid phenethyl ester synthesis. Comparing to conventional heating, microwave heating showed almost the same final conversion but increased initial reaction rate (3.03 mM/min) compared to 2.11 mM/min in conventional heating at $50^{\circ}C$.

One Pot Synthesis of Novel Cyanopyridones as an Intermediate of Bioactive Pyrido[2,3-d]Pyrimidines

  • Khatri, Taslimahemad T.;Shah, Viresh H.
    • 대한화학회지
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    • 제58권4호
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    • pp.366-376
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    • 2014
  • Synthesis, structural characterization, and biological activity studies of novel pyrido[2,3-d]pyrimidines (10a-h, 11a-h) are described. Cyclization of cynoacetamides (4, 5) with malonitrile (7) and aldehyde (6a-h) via Hantzsch pyridine synthesis afforded cyanopyridones (8a-h, 9a-h), which on cyclization with formic acid under microwave conditions led to the final product. All the reactions are significantly faster and the isolated yields are remarkably higher in microwave conditions compared to the conventionally heated reactions. The compounds were tested in vitro for their antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtillus, Staphylococcus aureus, and Micrococcus luteus and antifungal activity against Trichphyton longifusus, Candida albicans, Microsporum canis, Fusarium solani. Compounds 10b, 10e, 11b and 11e exhibited good antibacterial and antifungal activities compared with standards.

A Facile Solvent and Catalyst Free Synthesis of New Dihydro Pyrimidinones as Antimicrobial Agents

  • Hegde, Hemant;Ahn, Chuljin;Gaonkar, Santosh L.;Shetty, Nitinkumar S.
    • 대한화학회지
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    • 제63권6호
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    • pp.435-439
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    • 2019
  • An efficient one pot multicomponent synthesis of pyrimidinone derivatives of Biginelli type is described. 4-amino-6-aryl-pyrimidine-5-carbonitrile molecules were synthesized efficiently via three-component Biginelli-type condensation of aldehyde, malononitrile, and semicarbazone as urea substituent in the presence of a catalytic amount of PEG-400 as green medium under microwave irradiation. The reactions proceeded efficiently in the presence of microwave radiation to afford the desired products in good to excellent yields. Products have been confirmed by IR, and NMR spectral analysis. All the molecules were tested for their antimicrobial activity against E. coli, S. aureus, P. aeruginosa and C. tropicalis. Some of the compounds have shown moderate to good inhibition efficiency against both gram-positive and gram-negative bacteria. The potent activity was observed against the fungal species with minimum inhibition concentration 12.5 ㎍/mL.