Synthesis and Molluscicidal Activity of New Chromene and Pyrano[2,3-c]pyrazole Derivatives
作者:Fathy M. Abdelrazek、Peter Metz、Olga Kataeva、Anne Jäger、Sherif F. El-Mahrouky
DOI:10.1002/ardp.200700157
日期:2007.10
derivatives 13a–d to afford the arylidene exchange derivatives 14a–c and the pyranopyrazole derivative 15, respectively. The arylidene derivatives 10a, b react also with indane‐1,3‐dione 16 to afford the arylidene exchange derivatives 18a, b. The molluscicidalactivity of the synthesized compounds towards Biomphalaria alexandrina snails, the intermediate host of Schistosoma mansoni, was investigated and most
1,3-Dipolar cycloaddition of nitrones with nitriles.
作者:Pedro H.H. Hermkens、Jan H.v. Maarseveen、Chris G. Kruse、Hans W. Scheeren
DOI:10.1016/s0040-4020(01)89838-0
日期:——
nitriles 14–16, proceeded under thermal as well as underhighpressure conditions with complete regioselectivity to give Δ4-1,2,4-oxadiazolines 17–19. In general, the cycloaddition seemed to be controlled by a HOMO(nitrone)- LUMO(nitrile) interaction. However, a crossover in the orbital control is probable observed with nitrile 16c. Nitrone-nitrile cycloadditions are normal typeII cycloadditions so that
can undergo remoteFriedel-Crafts reaction with electrophilic reagents via a HOMO-activation strategy, proceeding in a formal vinylogous Rauhut-Currier or Morita-Baylis-Hillman-type reaction pattern. Moreover, even less reactive α-(2-benzofuranyl)-substituted cyclopeten-2-ones can be similarly HOMO-raised and furnish [4 + 2] products with alkylidenemalononitriles in a cascade Friedel-Crafts/Michael addition
heterogeneous catalyst for the synthesis of naphthopyrans by one-pot three-component reaction of naphthols, aldehydes, and malononitrile in EtOH/H2O (1:1) solvent medium. A comparative study of Ni–Al2O3 with neutral Al2O3 revealed that reactions with the former afforded better product yields, indicating higher catalytic efficacy. Ni–Al2O3 due to its lowcost, good activity, ease of handling, and easy recovery
摘要 Ni–Al 2 O 3是一种高效且可重复使用的非均相催化剂,用于在EtOH / H 2 O(1:1)溶剂介质中通过萘酚,醛和丙二腈的一锅三组分反应合成萘并吡喃。Ni-Al 2 O 3与中性Al 2 O 3的比较研究表明,与前者的反应提供了更高的产物收率,表明具有更高的催化效率。Ni-Al 2 O 3的价格低,活性好,易于处理,易于回收,产率高,纯化方法简单等特点使该方法具有很高的适用性。 图形概要
Synthesis and Molluscicidal Activity of New Cinnoline and Pyrano [2,3-c]pyrazole Derivatives
作者:Fathy M. Abdelrazek、Peter Metz、Nadia H. Metwally、Sherif F. El-Mahrouky
DOI:10.1002/ardp.200600057
日期:2006.8
reflux in acetic acid, these compounds were acetylated to give the cinnoline derivatives 9. The pyrazolones 10a, b react with 3‐furfurylidene‐ and 3‐thienylidene‐malononitrile derivatives 11a, b to afford the pyrano[2,3‐c]pyrazolederivatives 13a–d. These newly synthesized compounds show generally a moderate molluscicidalactivity to Biomphalaria alexandrina snails.