Four component and solvent‐free synthesis of some new spiro‐1,4‐dihydropyridines on solid support montmorillonite K10

A series of some new spiro‐1,4‐dihydropyridine derivatives have been synthesized in good yields in a four component, and solvent‐free process by condensation of isatins, primary amines, ethyl cyanoacetate and cyclohexanone on solid support montmorillonite K10     

A stereoselective three‐component reaction: One‐pot synthesis of cis‐isoquinolonic acids catalyzed by silica sulfuric acid under mild and heterogeneous conditions

A mild and stereoselective three‐component one‐step synthesis of cis‐isoquinolonic acid using silica sulfuric acid as a heterogeneous catalyst from an aldehyde, amine and homophthalic anhydride in acetonitrile is described. This new method produces pure products in high yields (81‐91%).     

Nanocrystalline magnesium oxide: a novel and efficient catalyst for facile synthesis of 2,4,5-trisubstituted imidazole derivatives

Abstract  

Nanocrystalline magnesium oxide with high specific surface area has been used as a novel and efficient catalyst for an improved and rapid synthesis of biologically active 2,4,5-trisubstituted imidazoles, by three-component, one-pot condensation of 1,2-diketones and aryl aldehydes, in excellent yields under solvent-free and conventional heating conditions. The method has several advantages, for example excellent yields, shorter reaction time, and use of a non-toxic and recyclable catalyst.     

1- and 2-D NMR Studies on [Rh6C(CO)14(PPh3)]2−

A complete NMR study involving both 1D and 2D ¹³C-{¹⁰³Rh} and ³¹P-{¹⁰³Rh} HMQC measurements, on [Rh₆C(CO)₁₄(PPh₃)]^2- are reported and discussed, together with the multiple Rh quantum effects found for resonances associated with edge- and face-bridging CO's. As found in [Rh₆C(CO)₁₅]^2-, the carbonyl ligands in [Rh₆C(CO)₁₄(PPh₃)]^2- undergo CO-intermolecular exchange with ¹³CO at different rates; for the edge-bridging CO's, the lower the value of ¹J(Rh–CO), the faster the rate of intermolecular exchange with ¹³CO.     

A novel one‐pot procedure for preparation of some new condensed pyrido[2,3‐d]pyrimidine(1H,3H)‐2,4‐diones

A novel one‐pot procedure for preparation of some new condensed pyrido[2,3‐d]pyrimidine(1H,3H)‐2,4‐diones based on condensation of ninhydrin, alkyl cyanoacetate, and 6‐aminouracil derivatives has been reported. The reactions were carried out in refluxed ethanol and were completed in less than 2 h. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:16–18, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20242     

Acet­amidoxime

The oxime of acet­amide, viz. N‐hydroxy­ethanimid­amide, C₂H₆N₂O, has a complex hydrogen‐bonding arrangement in its crystal structure, featuring one strong O—H⋯N hydrogen bond together with weaker hydrogen bonding involving the amide groups. Conjugation effects lead to atypical distances and angles.