Organic Communications Articles

Diarylpentanoids, having Ar-C5-Ar chain, are a small class of natural products, most of which have been discovered in last the decade. This review comprises 20 natural diarylpentanoids, including their isolation, characterization and biological activities.

Naphthoquinones are medicinally important molecules with a diverse array of biological properties such as antimicrobial, antifungal, antiviral, anti-inflammatory, anti-artherosclerotic and anticarcinogenic activities. In this study, we report the simple and direct preparation of a new group of novel menadione-hydrazone conjugates by reaction of 2-methyl-1,4-naphthoquinones with several aliphatic, aromatic and nucleobase hydrazides. The menadione-hydrazone conjugates were produced in excellent yields and characterized by IR, NMR and HRMS. The menadione derivatives were tested for their anticancer effects against human colon cancer HCT116 and human breast cancer MCF-7 cell lines. Interestingly, the molecules displayed disparate activities against both cell lines; the menadione hydrazones derived from the lipophilic myristic hydrazide and stearic hydrazide exhibited the most potent activity against HCT116 cell lines with IC50 of 89 and 64 μM. The most effective compounds against MCF-7 cells were the lauric hydrazide and benzoic hydrazide-derived menadione hydrazones with IC50 of 56 µM.

The reaction between 1,3-cyclohexadiene and dimethyl 7-oxabicyclo[2.2.1]hepta-2,5-diene-2,3-dicarboxylate both without a catalyst and with different catalysts, in both atmospheric and at high pressure, over 20 days were studied. At the end of the reactions, different products (retro Diels-Alder addition product 5 and Diels-Alder addition product 6 ) were obtained in different yields. When we look at the percentage of the addition product, it is observed that the yield of reaction at high pressure in water is the highest. All structures of these products were characterized by 1H-NMR, 13C-NMR, MS, and IR spectroscopy.

A new series of spiro 1,2,4-triazoles 5-9a-j were prepared by the reaction of appropriate amidrazones 4 with cyclic ketones in catalytic amount of p-toluene sulfonic acid. The structures of the titled compounds have been elucidated by the elemental analysis and spectroscopic data (IR, 1H NMR, 13C NMR and MS). The biological activities of the prepared compounds were investigated using well-established methods from the literature.

An efficient one pot synthesis of 2-arylbenzothiazole derivatives through condensation of aldehydes and 2-aminothiophenol in the presence of catalytic amount of La(NO 3) 3 · 6H 2O under mild reaction conditions was developed. The key advantages of this protocol are short reaction time, high to excellent yields, simple work up, inexpensive catalyst and simple separation of pure product.

Novel nitroso acetal derivatives (4-methyl-2,3,3a,6-tetrahydroisoxazolo[2,3-b][1,2]oxazine) were synthesized through 6π-electrocyclization/[3+2]-cycloaddition reaction of several dionophiles with 1-nitro-2-methyl-1,3-butadiene. Structures of the synthesized compounds were determined by 1H-NMR, 13C-NMR, IR and GC-MS analyses.

This article describes one-step synthesis of a singly bridged biscalix[6]arene ( 2 ) and evaluation of its recognition properties towards alkali metal ions for the first time. Synthesis of 2 was accomplished through coupling of two 4-tert-butylcalix[6]arene units with one molecule of diethyleneglycol ditosylate. Both base and linker were found to play a role in the outcome of coupling reaction for the simple and efficient synthesis of 2 . Complexation ability of 2 was studied by liquid-liquid extraction using alkali metal (Na +, K +, Cs +) picrates. Carrier activity of 2 towards the facilitated transport of alkali metal ions across a bulk liquid membrane was also studied and the transport behaviour was mechanistically explained. The predominant role of an ion exchange action mechanism in the transport process was observed.

(3R,5R)-7-(3-(phenylcarbamoyl)-5-(4-fluorophenyl)-2-isopropyl-4-phenyl-1H-pyrrol-1-yl)-3,5-dihydroxy-heptanoic acid, calcium salt (2:1)trihydrate (1), a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, was demonstrated to be effective in reducing both triglyceride and cholesterol. In present communication, two novel impurities i.e.,2-acetyl-4-(4-fluorophenyl)-4-oxo-N,3-diphenylbutanamide (18) and 2-(2-(3-fluoro phenyl)-2-oxo-1-phenylethyl)-4-methyl-3-oxo-N-phenylpentanamide (19)of 2-(2-(4-fluorophenyl)-2-oxo-1-phenylethyl)-4-methyl-3-oxo-N-phenylpentanamide (2),were reported along with their identification and isolation. The compounds were characterized by spectral techniques such as IR, 1HNMR, 13C NMR and mass.