Letters in Organic Chemistry - Volume 12, Issue 10, 2015

A clean and environmentally benign route to 2-amino-4H-chromenes has been developed using the reaction between various benzaldehydes, malononitrile and α-naphthol in the presence of 3,3'-(pentane-1,5-diyl)bis(1,2-dimethyl-1H-imidazol-3-ium) bromide. The present methodology offers several advantages such as solvent-free conditions, excellent yields, simple procedure, mild conditions and reduced environmental consequences. The ionic liquid was recovered and reused. All of synthesized compounds were characterized by IR, NMR and Elemental analyses.

In this work, palladium nanoparticles/graphene/SBA-15 (Pd/G/SBA-15) nanocomposites were fabricated using a facile method and characterized by XRD, SEM, TEM, and FT-IR, respectively. The as-prepared Pd/G/SBA-15 exhibited high catalytic activity for the Suzuki coupling reaction. The catalyst can be easily recycled and reused at least four times without a remarkable loss of its catalytic activity.

In this study some estradiol derivatives were prepared using different strategies. The first stage was achieved by the preparation of an estradiol-dicarbaldehyde derivative (compound 2) by the reaction of estradiol with dimethyl sulfoxide (method A) or with Cooper(II) reagent in the presence of ethylenediamine (method B). The following stage was achieved by synthesis of the steroid-oxadiazin ester derivative (compound 5) using the three-component system (compound 2, urea and anhydride succinic). Later, 5 was reacted with ethylenediamine to form the steroid-amino derivative (compound 6) using boric acid as catalyst. On the other hand, a steroid-acetamide derivative (compound 7) was synthesized by the reaction of 6 with chloroacetyl chloride in the presence of triethylamine. Finally, the compound 7 was reacted with 2-hydroxy-1-naphthaldehyde in basic medium to form a steroid-oxirane carboxamide derivative (compound 8). The structure of all compounds obtained was confirmed by spectroscopic and spectrometric methods.

Using various chromatography methods, five steroids and two brominated lipids (1-7), 3β- hydroxy-5-cholenic acid methyl ester, stigmasta-5,24(28)-dien-3β,29-diol, 24-methylenecholest-4-en- 3β,6β-diol, cholest-5-en-3β,7β-diol, 24-vinylcholest-5-en-3β,24-diol, xestospongiene A, and xestospongiene J, respectively, were isolated from the methanol extract of Vietnamese marine sponge Haliclona oculata (Linnaeus, 1759). Their structures were elucidated by 1D-, 2D-NMR, and ESI-MS spectra and in comparison with those reported in the literature. Compounds 1-4, 6, and 7 were reported from Chalinidae family for the first time. In addition, all compounds were evaluated for eight human cancer cell lines as HepG-2, KB, LU-1, MCF-7, LNCaP, HL- 60, SK-Mel2, and PC-3. As shown in results, compound 2 showed significant cytotoxic activities on KB and LU-1 cancer cell lines with the IC50 values ranging from 8.74 to 9.32 μM.

A highly efficient and environmentally benign protocol for the synthesis of 8-amino-6-aryl-1,2-dihydro-2-oxo-6H-pyrano[2,3-e]benzoxazole-7-carbonitrile derivatives by one-pot three-component coupling reacting of aromatic aldehydes, malononitrile and 4-hydroxy-2(3H)-benzoxazolone under reflux condition has been developed in aqueous media using Na2O-Al2O3-P2O5 glass-ceramic system.

An efficient and simple way to synthesize N-(β-nitroalkyl) amides with broad substrate spectrum was developed. Various β-nitroarylethanols and nitriles were suitable substrate for the protocol. A series of N-(β-nitroalkyl) amides were synthesized through Ritter reaction and the yield is up to 95%.

Seven heterocyclic compounds derived from isatin have been synthesized. Isatin was N-substituted with four aromatic/aliphatic and benzylic moieties (1a-d). Compounds 1a-c were condensed with o-phenylenediamine to afford indoloquinoxaline derivatives (2a-c). Products were tested as inhibitors of InhA enzyme of M. tuberculosis. Compound 6-(diethylaminoethyl)indoloquinoxaline (2a) inhibited 38% of InhA activity at 50 µM. The possible modes of interaction of 2a with InhA were explored by molecular docking. Docking experiments afford keys to improve compound 2a for the design of new potential active drugs against tuberculosis.

The use of multicomponent reactions as potential synthetic processes, ionic liquids as catalysts and water as reaction medium is a suitable approach that respects, in some extent, the requirements of sustainable chemistry. In this context, we report, herein, an efficient and high yielding four-component synthesis of 6-amino-4-aryl-3-methyl-2,4-dihydropyrano[2,3-c]pyrazole-5-carbonitriles involving ethyl acetoacetate, hydrazine hydrate, malononitrile, and various aromatic aldehydes using octyltriphenylphosphonium bromide as an effective and recoverable catalyst and water as solvent under mild reaction conditions.

An effective and improved process for the preparation of cis-cyclopro panediamine dihydrochloride was developed in a 100 g scale. The key step in the process is the preparation of ciscyclopropane- 1, 2-dicarboxylic acid from a mixture of cis- and trans- isomers by the formation of cyclic acidic anhydride. The whole process and all of the procedures are economical, industrially reliable and easily scaled up.

This work demonstrates the effective total synthesis of a new broad-spectrum parenteral carbapenem starting from the readily available and inexpensive N-Cbz-protected glycine amide in high yield with easy work-up under mild reaction conditions.

Novel series of 2-(4-chloro,6-morpholino-1,3,5-triazin-2-yl) amino acid ester derivatives and 2-(4,6-dimorpholino-1,3,5-triazin-2-yl) amino acid ester derivatives were synthesized using simple one pot method in acetone–water in the presence of K2CO3 as HCl scavenger. The products were obtained in high yields and purities as observed from their spectral data, elemental analyses and mass spectra. The anti-proliferation activities have been measured in MTT-Assay using two different cell lines the cervix carcinoma cell line (Hela), and the hepatocyte carcinoma (HepG2). The analysis showed that none of the prepared compounds showed growth inhibition activity on Hela cells. However only the 4-aminobenzoic ester derivatives showed a moderate inhibition effect on the hepatocellular carcinoma HepG2, the measured IC50 values were 48µg mL-1 and 39µg mL-1, respectively.