http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 주제어 : Biginelli Reaction (검색결과 2 건)
-
왕겨 실리카와 VSB-5를 이용한 Biginelli 반응 및 크롬산음이온 흡착
이화영 전북대학교 교육대학원 2008 국내석사
InCl3, CoCl2, FeCl3-impregnated microporous catalysts were prepared by impregnating InCl3, CoCl2, FeCl3 dissolved in acetonitrile to various microporous materials. Biginelli reactions under solvent-free conditions were investigated using microwave by the method of one-pot three-component condensation of urea, benzaldehyde and ethyl acetoacetate. Nanopore Silica was prepared by using Korean rice husk. The porous materials or Lewis acid modified porous materials, such as VSB-5, Nanopore Silica, InCl3/VSB-5, InCl3/Nanopore Silica, CoCl2/VSB-5, CoCl2/Nanopore Silica, FeCl3/VSB-5 and FeCl3/Nanopore Silica were used as catalysts. The Biginell reaction results of Nanopore Silica, InCl3/Nanopore Silica, CoCl2/Nanopore Silica and FeCl3/Nanopore Silica catalysts were compared. When Nanopore Silica was used as a catalyst, the yield of the Biginelli product was in the range of 65~68%. The sorption of chromate anion was carried out using the CTABr modified Silica and VSB-5. Since cetyltrimethylammonium(CTA) ion is too large to enter into the internal surface of Silica, the sorption of CTA ion seems to be only occurred on the external and wide internal surfaces. However since the pore size of VSB-5 is too small, only externed surface of VSB-5 could be occupied by the cationic surfactant. While the unmodified Silica and VSB-5 had no affinity for the chromate anion, the surfactant modified porous materials showed the moderately enhanced sorption of the oxyanion from aqueous solution. The sorption of chromate seems to be due to entropic, Coulombic and hydrophobic effects.
-
염화철, 염화인듐을 입힌 SBA-15를 촉매로 마이크로웨이브를 이용하여 디하이드로피리미디논을 무용매 상태에서 한단계 합성
In recent times, dihydropyrimidinone derivatives have attracted considerable attention owing to their high activities as antihypertensive, antiviral, antitumor, anti-inflammatory agents, and calcium channel blockers. The original procedure for the preparation of this type of compounds was reported by Biginelli in 1893, involving one-pot condensation of ethyl acetoacetate, benzaldehyde, and urea under strongly acidic conditions. An efficient synthesis of 3,4-dihydropyrimidinones using indium chloride and ferric chloride heptahydrate as a catalyst from an aldehyde, β-keto estaer and urea or thiourea in ethanol is described. This one-pot method consistently has the advance of good yields. Molecular sieves and mesoporous materials, due to their acidic and shape-selective nature, have been found to be a suitable replacement for various homogeneous acid catalysts.In this study, a SBA-15 catalyzed, single step and environmentally friendly process for the synthesis of dihydropyrimidinones is reported. FeCl3 and InCl3 supported SBA-15 catalysts were prepared, characterized and tested in microwave assisted solvent-free condition. This method has provided several advantages such as excellent yield, mild reaction condition, easy of workup, tolerance of other functional groups, and much shorten reaction time in comparison to the classical Biginelli reaction.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
