Selective hydrolysis of α-oxo ketene N,S-acetals in water: switchable aqueous synthesis of β-keto thioesters and β-keto amides

• Haifeng Yu,
• Wanting Zhang,
• Xuejing Cui,
• Zida Liu,
• Xifu Zhang and
• Xiaobo Zhao

Beilstein J. Org. Chem. 2024, 20, 2225–2233, doi:10.3762/bjoc.20.190

• N,S-acetals; β-keto amide; β-keto thioester; dodecylbenzenesulfonic acid; hydrolysis; Introduction In the past decades, the application of easily available and stable α-oxo ketene N,S-acetals as significant synthons has received more and more attention in organic synthesis due to their unique

• form adduct I', which is then transformed into intermediate II' by elimination of ethanethiolate. Subsequently, β-keto amide 3a is obtained when II' releases H+. Conclusion In summary, we have successfully developed an environmentally friendly method for the selective aqueous synthesis of β-keto

Synthetic approach to 2-alkyl-4-quinolones and 2-alkyl-4-quinolone-3-carboxamides based on common β-keto amide precursors

• Yordanka Mollova-Sapundzhieva,
• Plamen Angelov,
• Danail Georgiev and
• Pavel Yanev

Beilstein J. Org. Chem. 2023, 19, 1804–1810, doi:10.3762/bjoc.19.132

• intermediate β-enamino amides 2 are easily available by condensation of the corresponding β-keto amide 1 and an amine (Scheme 1, conditions i). As the amine here plays only an auxiliary role, for the purpose of this research we opted for inexpensive ethylamine. Compounds 2 were obtained by simply stirring a

A one-pot electrochemical synthesis of 2-aminothiazoles from active methylene ketones and thioureas mediated by NH₄I

• Shang-Feng Yang,
• Pei Li,
• Zi-Lin Fang,
• Sen Liang,
• Hong-Yu Tian,
• Bao-Guo Sun,
• Kun Xu and
• Cheng-Chu Zeng

Beilstein J. Org. Chem. 2022, 18, 1249–1255, doi:10.3762/bjoc.18.130

• protocol proceeds in an undivided cell equipped with graphite plate electrodes under constant current conditions. Various active methylene ketones, including β-keto ester, β-keto amide, β-keto nitrile, β-keto sulfone and 1,3-diketones, can be converted to the corresponding 2-aminothiazoles. Mechanistically

• performed in an undivided cell with NH4I as the mediator and cheap graphite plate as the working electrode. Various active methylene ketones, including β-keto ester, β-keto amide, β-keto nitrile, β-keto sulfone and 1,3-diones proved to be compatible with the protocol. Since external oxidants and

Pyridinoacridine alkaloids of marine origin: NMR and MS spectral data, synthesis, biosynthesis and biological activity

• Louis P. Sandjo,
• Victor Kuete and
• Maique W. Biavatti

Beilstein J. Org. Chem. 2015, 11, 1667–1699, doi:10.3762/bjoc.11.183

• -nitrobenzoyl)acetate to give a β-keto amide. The resulting amide was subjected to a Knorr cyclization in the presence of polyphosphoric acid to afford a quinolinone, which was further reduced to a quinoline in two steps. The Sandmeyer reaction permitted the replacement of the amide function with a carboxylic

An efficient method for the construction of polysubstituted 4-pyridones via self-condensation of β-keto amides mediated by P₂O₅ and catalyzed by zinc bromide

• Liquan Tan,
• Peng Zhou,
• Cui Chen and
• Weibing Liu

Beilstein J. Org. Chem. 2013, 9, 2681–2687, doi:10.3762/bjoc.9.304

• -aryl β-keto amides as the substrates in this protocol, 4-pyridones are resulted, however, when using N-aliphatic-substituted β-keto amides as the partners of N-aryl β-keto amides under the same conditions, 2-pyridones are afforded. Keywords: β-keto amide; phosphorus pentoxide; 2-pyridones; 4-pyridones

• ; self-condensation; Introduction β-Keto amide and their derivatives are desired classes of intermediates for the synthesis of nitrogen- and oxygen-containing heterocyclic compounds since they possess six reactive sites in the same molecule (Scheme 1) [1][2][3][4][5][6][7]. A lot of reports can be found

Organic synthesis using (diacetoxyiodo)benzene (DIB): Unexpected and novel oxidation of 3-oxo-butanamides to 2,2-dihalo-N-phenylacetamides

• Wei-Bing Liu,
• Cui Chen,
• Qing Zhang and
• Zhi-Bo Zhu

Beilstein J. Org. Chem. 2012, 8, 344–348, doi:10.3762/bjoc.8.38

• , exemplified by the formation of 2a, is depicted in Scheme 6. Initially, the reaction involved generation of the known chlorinating agent (dichloroiodo)benzene (PhICl2) [39], followed by dichlorination of the β-keto amide of 3-oxo-N-phenylbutanamide (1a) to give intermediate 4. It is well known that Lewis

• carbonyl carbon atom affords intermediate 7. A subsequent carbon–carbon bond cleavage of the labile α,α-dichloro β-keto amide through a retro-Claisen condensation reaction [41] generates intermediate 8. Finally, the electrophilic attack of a proton on the carbon–carbon double bond resulted in the final

An overview of the key routes to the best selling 5-membered ring heterocyclic pharmaceuticals

• Marcus Baumann,
• Ian R. Baxendale,
• Steven V. Ley and
• Nikzad Nikbin

Beilstein J. Org. Chem. 2011, 7, 442–495, doi:10.3762/bjoc.7.57

• ). An attractive alternative synthesis of sunitinib introduces the amide side chain earlier by ring opening of 4-methyleneoxetan-2-one (43) with N,N-diethylethane-1,2-diamine (44) [10]. The resulting β-keto amide 45 is then converted to the analogous pyrrole by condensation with the previously mentioned