Direct Amidation of Carboxylic Acids with Nitroarenes
作者:Shao-Peng Wang、Chi Wai Cheung、Jun-An Ma
DOI:10.1021/acs.joc.9b02068
日期:2019.11.1
N-Aryl amides are an important class of compounds in pharmaceutical and agrochemical chemistry. Rapid and low-cost synthesis of N-aryl amides remains in high demand. Herein, we disclose an operationally simple process to access N-aryl amides directly from readily available nitroarenes and carboxylicacids as coupling substrates. This method involves the in situ activation of carboxylicacids to acyloxyphosphonium
chromium-catalyzed activation of acyl C–O bonds with magnesium for amidation of esters with nitroarenes. Low-cost chromium(III) chloride shows high reactivity in promoting amidation by using magnesium as reductant and chlorotrimethylsilane as additive. It provides a step-economic strategy to the synthesis of centrally important amide motifs using inexpensive and air-stable nitroarenes as amino sources.
A VERSATILE AND CONVENIENT SYNTHESIS OF ALKYL NITROAROMATIC ETHERS BY NUCLEOPHILIC AROMATIC SUBSTITUTION
作者:Richard A. Bunce、Kerry M. Easton
DOI:10.1080/00304940409355375
日期:2004.2
benzoxazines.' During the preparation of several of these substrates, we found that conversion of the required allylic alcohol to the bromide and 0-alkylation of 2-nitrophenol under basic conditions gave low yields of the desired products. We, therefore, sought a more direct approach involving nucleophilic substitution of an allylic alkoxide on 2-fluoro-lnitrobenzene. Nucleophilic aromatic substitution
3-aryl-4(3H)quinazolinone CCK antagonists and pharmaceutical
申请人:Eli Lilly and Company
公开号:US05075313A1
公开(公告)日:1991-12-24
Novel substituted quinazolinones have been found to exhibit specific binding to cholecystokinin (CCK) receptors in the brain and/or peripheral site such as the pancreas and ileum. The quinazolinones are CCK receptor antagonists and find therapeutic application in the treatment of gastrointestinal disorders and central nervous system disorders, and are useful for appetite regulation in mammals. Pharmaceutical formulations for such indications are described.
The invention concerns cholecystokinin (CCK) antagonists useful in the treatment of cognitive disorders. Especially useful are CCKB antagonists such as CI-988.