brominated β-ketoesters with nitriles to generate enamino-substituted keto esters. The best results were obtained when a combination of indium metal (0.7 equiv.) with indium trichloride (1.6 equiv.) were applied at 60 °C for 20 to 72 hours, and these conditions could be applied to a broad range of nitriles and a significant number of different β-ketoesters. The transformation of aliphatic nitriles proved
One-Pot Synthesis of Highly Substituted Nicotinic Acid Derivatives Based on a Formylation Strategy of Enamino Keto Esters
作者:Sukeerthi Kumar、Aarti A. Sawant、Rajendra P. Chikhale、Keya Karanjai、Abraham Thomas
DOI:10.1021/acs.joc.5b02796
日期:2016.2.19
A facile one-pot synthesis of 4-chloro or 4-bromonicotinic acidesters with optional 2- and 2,5-disubstitution on the pyridine ring has been developed from easily accessible enamino keto esters by a formylation followed by in situ intramolecular cyclization strategy under optimized Vilsmeier reaction conditions. The effect of the substituents on the β-carbon and the nature of the keto functionality
There is provided a series of substituted acyl guanidines of Formula (I)
or a stereoisomer; or a pharmaceutically acceptable salt thereof, wherein R
1
, R
2
, R
3
, R
4
and R
5
as defined herein, their pharmaceutical compositions and methods of use. These compounds inhibit the processing of amyloid precursor protein (APP) by β-secretase and, more specifically, inhibit the production of Aβ-peptide. The present disclosure is directed to compounds useful in the treatment of neurological disorders related to β-amyloid production, such as Alzheimer's disease and other conditions affected by anti-amyloid activity.