Facile Method for the Synthesis of Cyanoacrylates by Knoevenagel Condensation
作者:Thabile Mabaso、Nhlanhla Gracious Shabalala、Nagaraju Kerru、Sreekantha B. Jonnalagadda
DOI:10.1080/00304948.2020.1831894
日期:2021.1.2
(2021). Facile Method for the Synthesis of Cyanoacrylates by KnoevenagelCondensation. Organic Preparations and Procedures International: Vol. 53, No. 1, pp. 18-24.
Radiographic element with UV absorbation compound in polyester support
申请人:Eastman Kodak Company
公开号:US05215876A1
公开(公告)日:1993-06-01
A radiographic element comprises a polyester support having double sided silver halide emulsion layers. An ultraviolet light absorbing methine compound is copolymerized with the support and is present in an amount sufficient to reduce the average percent transmission of ultraviolet light over the range of wavelength of from about 350 nm to about 395 nm to less than about 25 percent, and whereby the percent transmittance of said element is at least about 55 percent at a wavelength of about 410 nm for an element thickness of about 0.007 inches.
Esterification of carboxylic acid is achieved using acetonitrile as a water trap. Water liberated during esterification is consumed in cyanide hydrolysis, thereby driving the esterification to completion. Substrates having carboxylic acid and nitrile groups undergo intramolecular dehydration and rehydration to amido esters in the absence of acetonitrile. Cyano acids also undergo esterification and Ritter reaction in one pot when excess alcohol is used. For the first time, we have observed an interesting Ritter reaction of primary alcohols, leading to ester amide product in one pot. [Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications (R) for the following free supplemental resource(s): Full experimental and spectral details.]
One-Pot Synthesis of γ-Azidobutyronitriles and Their Intramolecular Cycloadditions
作者:Ekaterina M. Budynina、Konstantin L. Ivanov、Hamidulla B. Tukhtaev、Feruza O. Tukhtaeva、Stanislav I. Bezzubov、Mikhail Ya. Melnikov
DOI:10.1055/s-0040-1706402
日期:2020.11
was demonstrated by their transformation into tetrazoles via intramolecular (3+2)-cycloaddition. A condition-dependent activation effect of the α-substituent was revealed in that case. Thermally activated azide–nitrile interaction did not differentiate the presence of an α-electron-withdrawing substituent in γ-azidonitriles, whereas the Lewisacidmediated (SnCl4 or TiCl4) reaction proceeded much easier