Cascade Synthesis of 2-Cyanoacrylamides through Deacetalization and/or Knoevenagel Condensation followed by Selective Monohydration of Acetals and Aldehydes over Solid Acid Ferrites
作者:Sumit B. Kamble、Chandrashekhar V. Rode
DOI:10.1002/cctc.201600426
日期:2016.8.22
involving deacetalization and/or Knoevenagel condensation followed by selective monohydration of nitriles starting from acetals (5) and aldehydes (2) with malononitrile (3). A series of aldehydes, dimethyl and diethyl acetals, along with some heterocyclic aldehydes were successfully transformed to 2‐cyanoacrylamides with >95 % yields. TEM images confirmed the coating of the PVP over nanosized Fe3O4
提出了一种新的生物活性2-氰基丙烯酰胺级联合成的方案(1)。该反应在回流条件下,在AcOH-H 2 O介质中,通过一种新型的可磁性回收的固体酸复合物进行,该复合物是氧化铁,聚(乙烯基吡咯烷酮)和磷钨酸(Fe 3 O 4 / PVP-PWA)。通过单中心布朗斯台德酸催化的级联反应(包括脱缩醛和/或Knoevenagel缩合反应,然后由乙缩醛(5)和醛(2)与丙二腈(3)选择性地单水合腈),可以促进这种转化。)。一系列醛,二甲基和二乙基乙缩醛以及一些杂环醛已成功转化为2-氰基丙烯酰胺,收率> 95%。TEM图像证实了PVP在纳米Fe 3 O 4上的涂层。NOESY实验证明了2-苄叉基丙二腈(4)立体选择性单水合为E异构体。由于使用了缩醛和醛,因此该催化剂具有磁性,因此可以有效地循环使用七次。
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.