Letters in Organic Chemistry - Volume 12, Issue 2, 2015

A mild, simple and efficient procedure for the preparation of 3,4-dihydropyrimidin-2(1H)-ones and 3,4,7,8- tetrahydroquinazoline-2,5-diones is described using pyridinium p-toluenesufonate as an efficient catalyst under mild conditions. Simple methodologies, easy work-up procedure, excellent yields and very short reaction times are among the other advantages of this work.

Novel spiro bis-crown ethers derivatives with four benzo units connected via one carbon bridges have been prepared. These compounds represent well preorganized cavities with interesting complexation abilities towards cations. These macrocyclic were prepared by a four-step via template method by utilizing simple precursors catechol, oliethylen glycol and penta erythritol tetra bromide in good yield. Additionally, cesium ca Read More

Five newly synthesized bent-shaped compounds containing azobenzene chromophores have been prepared by resorcinol esterification with 4-(4-alkyloxyphenylazo) benzoic acid using DCC and DMAP. The structure of newly synthesized compounds was confirmed by MS and FT-IR spectroscopy. In addition, NMR spectroscopy also established the purity of these compounds. According to their azo-type chemical structure, the newly Read More

The synthesis of a number of poly functionalized furans by an efficient route involving a three-component condensation reaction between cyanoacetamide and arylaldehydes in the presence of cyclohexyl isocyanide is reported.

A microwave assisted multi-component reaction involving 2-amino-1,3,4-thiadiazoles, aromatic aldehydes and thioglycolic acid as substrates, afforded a series of novel 2-(1,3,4-thiadiazolo)-3-aryl-4-thiazolidinones in good yields.

Molecular complexes of monoammonium glycyrrhizinate (glycyram) with triterpene glycosides from ivy alpha- hederin (hederagenin 3-O-α-L-rhamnopyranosyl-(1→2)2)-O-α-L-arabinopyranoside) and hederasaponin C (hederagenin 3-O-α-L-rhamnopyranosyl-(1→2)-O-α-L-arabinopyranosyl-28-0-α-L-rhamnopyranosyl-(1→4)-0-β-D-glucopyranosyl-( 1→6)-0-β-D-glucopyranoside) have been prepared for the first time. The compl Read More

The C-S bond formation reaction has been described by the reaction of Bromo-barbituric acid with ammonium aryl dithiocarbamates in the presence of Amberlyst-15 as a reusable catalyst in aqueous medium. The mild reaction conditions, easy product isolation and good to high yields, are the major advantages of present protocol.

N-Substituted tetrazole was attempted to formylate which led to the formation of a novel triazene by opening of tetrazole ring via unusual Vilsmeir-Haack reaction. The formed product was proved by spectral analyses and X-Ray diffraction studies.

Silica supported aluminum nitrate (Al(NO3)3·9H2O) was found to be an excellent reagent for the nitration of phenols and phenyl ethers. This procedure works efficiently on most of the examples at room temperature yielding nitro derivatives in fair to good yields with high regioselectivity. The present methodology evidenced a considerable enhancement in the reaction rate along with high o-selectivity, excellent yields, eas Read More

Mononitration of activated aromatic compounds using N-methyl-2-chloro-pyridinium iodide (Mukaiyama reagent)/ NaNO2/wet SiO2 reagent system under neutral, very mild and environmentally safer reaction condition has been developed. Various structurally diverse aromatic rings are subjected in this condition and the corresponding nitro-aromatic compounds are prepared in moderately high yields.

(2S)-5-(3-Methyl-2-phthalimidylpentanoylamino)isophthalic acid (1), (2S)-5-(2-Phthalimidiylpropanoylamino) isophthalic acid, and (2S)-5-(3-phenyl-2-phthalimidylpropanoylamino)isophthalic acid were prepared from phthalic anhydride, 5-aminoisophthalic acid and the corresponding L-amino acids in acetic acid. The interfacial polycondensation of the corresponding diacid chlorides with two aromatic diazo containing diols such as 4, Read More

Triflic acid (5mol%) is an efficient catalyst, which firstly applied to the anti-Markovnikov intermolecular hydroamination of ethyl acrylate with 2-aminopyridines, sharply improves yields as high as 96%, reduces reaction times as short as 12h. Moreover, the post-reaction process involves simple recrystallization in petroleum ether to obtain products in purity as high as 99%. The reaction mechanism is verified by crossover Read More