21486-57-7Relevant articles and documents
One-Pot Synthesis of Highly Substituted Nicotinic Acid Derivatives Based on a Formylation Strategy of Enamino Keto Esters
Kumar, Sukeerthi,Sawant, Aarti A.,Chikhale, Rajendra P.,Karanjai, Keya,Thomas, Abraham
, p. 1645 - 1653 (2016)
(Chemical Equation Presented). A facile one-pot synthesis of 4-chloro or 4-bromonicotinic acid esters 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 were explored in detail to understand the mechanism of pyridine ring formation under the described conditions.
Electrochemical Iodine-Mediated Oxidation of Enamino-Esters to 2H-Azirine-2-Carboxylates Supported by Design of Experiments
Babaoglu, Emre,Hilt, Gerhard
supporting information, p. 8879 - 8884 (2020/07/15)
An electrochemical iodine-mediated transformation of enamino-esters for the synthesis of 2H-azirine-2-carboxylates is presented. In addition, a thermic conversion of azirines to 4-carboxy-oxazoles in quantitative yield without purification was described.
Expanding Blaise-Type Reactions towards Indium-Mediated Transformations of α-Bromo-β-keto Esters with Nitriles
Li, Luomo,Babaoglu, Emre,Harms, Klaus,Hilt, Gerhard
, p. 4543 - 4547 (2017/08/30)
The aim of this work is the identification of mild reaction conditions for the Blaise-type transformation of brominated β-keto esters 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-keto esters. The transformation of aliphatic nitriles proved to be difficult and gave only moderate yields. However, aromatic nitriles gave good yields in many cases. The applicability range of β-keto esters is acceptable while some electron-deficient aryl-substituents on the keto ester were challenging substrates. Nevertheless, we were able to expand the scope of the Blaise-type reaction towards brominated β-keto esters significantly.
Synthesis of β-enaminodicarbonyl derivatives in the titanium(iv) chloride-promoted reactions of β-dicarbonyl compounds with nitriles
Pei, Shuchen,Xue, Chenchen,Hai, Li,Wu, Yong
, p. 38055 - 38058 (2014/11/07)
Titanium(iv) chloride selectively promoted the nucleophilic attack of ethyl acetoacetate with nitriles to give enaminoketoesters, which were valuable intermediates for the syntheses of 2,3,4-substituted heterocyclics. Moreover a plausible mechanism for this transformation was given. the Partner Organisations 2014.
Four-component synthesis of functionalized 2,2′-bipyridines based on the Blaise reaction
Hommes, Paul,Jungk, Phillip,Reissig, Hans-Ulrich
scheme or table, p. 2311 - 2314 (2011/10/31)
In situ C-acylation of the Blaise intermediate - as reported by Lee and coworkers - provides α-acyl-β-enamino esters that are versatile building blocks for the preparation of N-heterocycles. The corresponding N-acylated β-ketoenamides can be employed in the synthesis of 4-hydroxypyridine derivatives. N-Acylation of the α-acyl-β-enamino esters with 2-picolyl chloride furnished β-ketoenamides, and the subsequent TMSOTf/base-promoted intramolecular condensation reaction led to 4-hydroxy-2,2′-bipyridine derivatives. Conversion into 2,2′-bipyrid-4-yl nonaflates allowed further functionalization such as palladium-catalyzed coupling reactions. Georg Thieme Verlag Stuttgart - New York.
ISOTHIAZOLE-PYRIDINE DERIVATIVES AS MODULATORS OF HIF (HYPOXIA INDUCIBLE FACTOR) ACTIVITY
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Page/Page column 49, (2009/09/04)
The present invention relates to novel compounds according to Formula I or II, methods, and compositions capable of decreasing HIF hydroxylase enzyme activity, thereby increasing the stability and/or activity of hypoxia inducible factor (HIF). Formula (I) or (II).
An effective and general method for the highly regioselective synthesis of 1-phenylpyrazoles from β-enaminoketoesters, tandem Blaise-acylation adducts
Ko, Young Ok,Chun, Yu Sung,Park, Cho-Long,Kim, Youngmee,Shin, Hyunik,Ahn, Sungho,Hong, Jongki,Lee, Sang-Gi
supporting information; experimental part, p. 1132 - 1136 (2009/05/30)
An effective and general route for the regioselective synthesis of 1-phenylpyrazoles has been developed from β-enaminoketoesters prepared by tandem Blaise-acylation. This method is applicable to a very broad range of substrates, generating a diverse set o
The first chemoselective tandem acylation of the Blaise reaction intermediate: A novel method for the synthesis of α-acyl-β-enamino esters, key intermediate for pyrazoles
Sung Chun, Yu,Kon Lee, Ki,Ok Ko, Young,Shin, Hyunik,Lee, Sang-Gi
supporting information; experimental part, p. 5098 - 5100 (2009/03/11)
The Blaise reaction intermediate, a zinc bromide complex of β-enamino ester, could be activated in situ by addition of a stoichiometric or catalytic amount of n-BuLi to allow chemoselective tandem C2-acylation providing α-acyl-β-enamino esters, which are
