Samarium Triflate–Catalyzed Biginelli Condensation: An Improved Method for the Synthesis of 3,4-Dihydropyrimidin-2(1H)-ones

Abstract

A simple and efficient method for multicomponant synthesis of 3,4-dihydropyrimidinones has been reported. All the reactions were carried out using samarium triflate as catalyst (10 mol%) at acetonitrile reflux. This procedure is applicable to a variety of substrates such as aliphatic, aromatic, and heterocyclic aldehydes.

Deprotection Chemistry Mediated by ZrOCl2 · 8H2O: An Efficient,Mild, and Green Method for the Conversion of Oximes to Carbonyl Compounds in Aqueous Acetone

Abstract

Less-toxic, moisture-stable, inexpensive, and ecofriendly zirconium oxychloride octahydrate (ZrOCl₂ · 8H₂O) in aqueous acetone (1:1) mediates the conversion of oximes to carbonyl compounds in moderate to good yields. This green methodology is applicable to both aldoximes and ketoximes with tolerance to >C?C<, -NO₂, -OH, and -Cl groups. The reaction and workup are simple.

Convenient and Efficient Synthesis of Some Novel Fused Thieno Pyrimidines Using Gewald's Reaction

Abstract

Several functionalized thienopyrimidines were synthesized by a facile synthetic method, which includes Gewald's reaction, and were characterized by spectral and analytical data. These functionalized thienopyrimidines were converted to various new chemical entities of biological importance, such as 2-piperazinymethyl thienopyrimidines (6, 8), 4-dimethylaminoethoxy thienopyrimidines (11), and 3-dimethylaminoethyl thienopyrimidines (12). All the compounds thus synthesized were screened for their invitro biological activities. Some of the compounds displayed promising serotonin 5-HT₆ receptor antagonist activities.

Silica Gel Promotes Cascade Synthesis of 2-(Heteroaryl)acetamide Derivatives from Isocyanides,Dialkylamines, and Heteroarylcarbaldehydes

Abstract

Addition of an isocyanide to an iminium ion intermediate that forms from the reaction between a heteroarylcarbaldehyde and a secondary amine leads to formation of sterically congested 2-(heteroaryl)acetamide derivatives in the presence of silica gel at room temperature. The structures of the products were deduced from their ¹ Tietze , L. F. ; Modi , A. Multicomponent domino reactions for the synthesis of biologically active natural products and drugs . Med. Res. Rev. 2000 , 20 , 304 .[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]H NMR, ¹³ Ugi , I. ; Steinbrückner , C. Über ein neues Kondensations-Prinzip . Angew. Chem. 1960 , 72 , 267 .[Crossref], [Web of Science ®] , [Google Scholar]C NMR, and infrared spectra and mass spectrometry.

Simple and Efficient One-Pot Synthesis of Nitriles from Amides and Oximes Using in Situ–Generated Burgess-Type Reagent

The dehydration of aldoximes and amides, and oxidation of benzoin are accomplished in one-pot using in situ–generated Burgess-type reagent.

Deoxygenation of Aromatic Ketones Using Transfer Hydrogenolysis with Raney Nickel in 2-Propanol

Aryl ketones are readily deoxygenated to their corresponding aryl alkanes upon treatment with Raney nickel catalyst in boiling 2-propanol.

Facile and Efficient Method for the Synthesis of 14-Substituted-14-H-dibenzo[a,j]xanthenes Catalyzed by Ruthenium Chloride Hydrate as a Homogeneous Catalyst

Synthesis of dibenzoxanthenes through condensation of β-naphthol with various aromatic and aliphatic aldehydes in ethanol as an ecofriendly solvent using Ru^III as catalyst is reported.

Improved Synthesis of Monoprotected 5- and 6-Amino-2-azanorbornanes

An improved synthesis of Boc-monoprotected 5- and 6-amino-2-azanorbornanes is reported. The synthetic scheme consists of five steps and allows multigram quantities of the title compounds to be obtained. The regio- and stereochemistries of the products are established by two-dimensional NMR experiments.

Novel Synthetic Routes of 3-Methoxypropanal from Glycerol

A new synthesis of 3-methoxypropanal from glycerol was presented. With this new approach, the conversion of glycerol to 3-methoxypropanal can be effected in moderate yield using catalysts of copper sulfate and polyethylene glycol (PEG).