Rapid synthesis of tetrahydro-4H-pyrazolo[1,5-a]diazepine-2-carboxylate
摘要:
Hydrazines condense with dimethyl 2-pyrrolidino-4-oxo-2-pentenedioate in the presence of aq. HCl to form N-substituted pyrazole-3,5-dicarboxylates 2. Complex bicyclic derivatives, such as pyrazolo-oxazine 3a, pyrazolo-oxazepine 3b, pyrazolopyrazine 4a, and pyrazolo-diazepine 4b, were generated using 2-hydrazinoethanol, 3-hydrazinopropanol, 2-hydrazinoethylamine, and 3-hydrazinopropylamine. (C) 2003 Elsevier Ltd. All rights reserved.
I2 catalysed sp3 C–H sulfonylation to synthesize β-dicarbonyl sulfones with sodium sulfinate as the sulfonyl source.
I2催化的sp3 C-H磺化反应,以亚砜钠作为磺酰基来源合成β-二羰基砜。
ZnCl<sub>2</sub>supported on Fe<sub>3</sub>O<sub>4</sub>@SiO<sub>2</sub>core-shell nanocatalyst for the synthesis of quinolines<i>via</i>Friedländer synthesis under solvent-free condition
Fe3O4@SiO2/ZnCl2 was prepared by supporting ZnCl2 on silica‐coated magnetic nanoparticles of Fe3O4. This recoverable catalyst was used for the synthesis of quinolines via Friedländersynthesisfrom 2‐aminoaryl ketones and α‐methylene ketones under solvent‐free condition. The prepared catalyst was characterized by FT‐IR, TEM, SEM, XRD, EDX, ICP‐OES, VSM and BET. It was found that Fe3O4@SiO2/ZnCl2 showed
通过将ZnCl 2负载在二氧化硅包覆的Fe 3 O 4磁性纳米粒子上,制备了Fe 3 O 4 @SiO 2 / ZnCl 2的磁性纳米催化剂。这种可回收的催化剂用于在无溶剂条件下通过2-氨基芳基酮和α-亚甲基酮通过Friedländer合成法合成喹啉。通过FT-IR,TEM,SEM,XRD,EDX,ICP-OES,VSM和BET对制备的催化剂进行表征。发现Fe 3 O 4 @SiO 2 / ZnCl 2的催化活性高于均相的ZnCl 2。,并且可以重复使用几次,而不会造成活动损失。
Remote stereocontrol as a synthetic strategy: diastereoselective annulations on an arene tricarbonylchromium template †
作者:Surojit Sur、Sambasivam Ganesh、Vedavati G. Puranik、Amitabha Sarkar
DOI:10.1039/a705285e
日期:——
Stereoselective annulations on Cr(CO)3 complexed tetralone and benzosuberone§ derivatives have been achieved. Diastereomeric products are shown to be related by an epimerisable chiral centre. An unusually facile de-ethoxycarbonylation has been observed.
Verfahren zur Herstellung von Imidazopyridinderivaten
申请人:LONZA A.G.
公开号:EP0645388A1
公开(公告)日:1995-03-29
Es wird ein neues Verfahren zur Herstellung von Imidazopyridinen der allgemeinen Formel
worin die Resten R₁ bis R₄ die in der Beschreibung angegebene Bedeutung haben, beschrieben.
Im Schlüsselschritt des Verfahrens wird ein Amidin der Formel
mit einer 1,3-Dicarbonylverbindung der allgemeinen Formel
cyclisiert.
Die Imidazopyridine sind wertvolle Zwischenprodukte zur Herstellung von Angiotensin-II-Antagonisten.