Letters in Organic Chemistry - Volume 12, Issue 7, 2015

A tandem metal-free synthesis of partly and fully substituted pyrimidines has been accomplished from α,β-unsaturated ketones and benzamidine in presence of triethyl amine. The reaction proceeds via [3+3] annulation-oxidation sequence and the protocol has been found successful for the synthesis of a wide range of pyrimidine derivatives.

Though L-dopa is an effective drug for Parkinson’s disease, the usage of L-dopa in clinical treatment is limited for its physico-chemical properties which affect the bioavailability of L-dopa and increase the side effects of L-dopa. For improving the availability of L-dopa, L-dopa-L-His was synthesized by Fmoc solid-phase peptide synthesis, purified by reversed-phase HPLC and characterized by using 1H, 13C NMR and ESI-M Read More

A clean, efficient and facile one-pot protocol was developed for the synthesis of a series of new 3,4-substituted coumarins (warfarin analogous compounds) by a one-pot reaction using catalytic amount of Fe3O4 nanoparticles under solvent-free conditions. This green method offers significant advantages in terms of its simplicity, low catalyst loadings, high product yields, recyclability of catalyst and non-toxic nature.

In this report, synthesis and characterization of silica perchloric acid nanosphere as a novel and heterogeneous catalyst are described. It has a spherical shape and the particle size is between 75 and 100 nm. The catalytic activity has been investigated in coupling reaction involving a variety of aldehydes, phthalhydrazide, dimedone at 80°C under solvent-free conditions. This method offers advantages such as good yields, sim Read More

Two efficient synthetic routes to (S,S)-ethambutol, a first line drug used for tuberculosis treatment, based on the chiral pool approach viewing L-methionine as a starting material are reported. Several advantages over the traditional synthetic routes were observed: simple, safe, inexpensive reagents, and minimum byproduct formation. The key intermediate (S)-(+)-2-amino-1-butanol was obtained in its enantiomerically pure Read More

The aromaticity index D, usually obtained by using DFT/B3LYP/6-311G+(d,p) theoretical method, was tested using different basis sets: aug-cc-pVDZ, aug-cc-pVTZ, aug-cc-pVQZ, LanL2DZ, LanL2MB, SDD, DGTZVP, and DGDZVP2 were used. The results showed the D values are not largely sensible to the variation of the basis set. D values were correlated to ERE and ASE. The best correlation between D and ERE was obtained by usin Read More

The replacement of platinum in carboplatin, oxaliplatin and nedaplatin by zinc metal (in bulk and nano-scalled) produces biologically active compounds with increased solubility in water. We compared, in this work, three synthesized zinc-complexes from the ligands of platinum-anticancer drugs. The structural characterization of the products has been determined on the basis of their atomic absorption spectroscopy, eleme Read More

An efficient one-pot synthesis of dihydropyrano[3,2-c]quinolones 4a-p by three-component reaction of N-methylquinoline-2,4-dione (1) with malononitrile (3a) or ethylcyanoacetate (3b) and benzaldehydes 2a-h in water in the presence of TBA acetate has been described. The above synthesis was also tried alternatively by the reaction of 1 with 2a-h in refluxing water using TBA acetate for 30 min and yielded 5. Comp Read More

A rigid shape-persistent fluorescent macrocycle PhenMac was synthesized using Sonogashira coupling reaction and TIPS-decoupling in a single pot. 2,9-dichloro-1,10-phenanthroline was reacted with TIPS-protected diyne 2 in the presence of Pd(PPh3)2Cl2, CuI and TBAF at 100 °C. PhenMac was obtained as yellow fluorescent compound; characterized by NMR, ESI, MALDI-TOF, CHN, IR and UVvisible spectroscopy. In chloroform, Ph Read More

Reaction of triphenylmethanol with acetylacetone in 1,2-dichloroethane medium in the presence of Cu(OTf)2 or Al(OTf)3 catalysts resulted in 3-(9-phenyl-9H-fluorene-9-yl)-pentanedione- 2,4 with 25% yield. 3-(9-Phenyl-9H-fluorene-9-yl)-pentanedione-2,4 was also obtained by an alternative synthesis between 9-phenylfluorene-9-ol and acetylacetone in the presence of Al(OTf)3 catalyst with practically quantitative yield.

The conformational behaviors of 2-fluoro-2-oxo-1,3,2- (compounds 1-3), 2-chloro-2-oxo- 1,3,2- (compounds 4-6), 2-bromo-2-oxo-1,3,2- (compounds 7-9), -dioxa, -dithia, -diselena phosphorinanes have been analyzed by means of hybrid density functional theory (B3LYP/6- 311+G**) and ab initio molecular orbital (HF/6-311+G**) based methods and NBO interpretation. The results justified the axial conformations preference of co Read More