A novel [1, 2, 4]triazolo[5,1-b]quinazoline derivative as a fluorescent probe for highly selective detection of Fe3+ ions.

A novel [1, 2, 4]triazolo[5,1-b]quinazoline fluorescent probe (VIi) for Fe3+ was developed, featuring with rapid response (< 5 s) and specific selectivity to Fe3+, low detection limit (1.3 × 10-5 M), as well as the ability to resist interference of chelating agent (e.g. EDTA). VIi-based fluorescent test paper can quickly recognize Fe3+ under irradiation at the wavelength of 365 nm. The fluorescence probe VIi has potential application prospects for the detection of Fe3+ in real circumstance.

A New Pathway for the Synthesis of Ketones from Aldehydes and Sulfonylhydrazones: Is Diazo the Key Intermediate?

A new pathway via a cyclic intermediate for the synthesis of ketones from aldehydes and sulfonylhydrazone derivatives under basic conditions is proposed. Several control experiments were performed along with analysis of the mass spectra and in-situ IR spectra of the reaction mixture. Inspired by the new mechanism, an efficient and scalable method for homologation of aldehydes to ketones was developed. A wide variety of target ketones were obtained in yields of 42-95 % by simply heating the 3-(trifluoromethyl)benzene sulfonylhydrazones (3-(Tfsyl)hydrazone) for 2 h at 110 °C with aldehydes and with K2 CO3 and DMSO as base and solvent, respectively.

Synthesis of 19-hydroxyprogesterone and insights into the ring-opening mechanism of the 6,19-epoxy bridge.

An efficient and scalable process for the synthesis of 19-hydroxyprogesterone was obtained through seven steps with 34.5% total yield, which is much higher than the process reported in the literature (11.0% total yield). The plausible ring-opening mechanism of 6,19-epoxy bridge in compound 7 was first proposed and the structures of intermediates were supported by the LC-MS analysis of the reaction mixture.

Synthesis and in vitro anti-epileptic activities of novel [1,2,4]-triazolo[1,5-a]pyrimidin-7(4H)-one derivatives.

In this investigation, eight novel 2,5-disubstituted [1,2,4]-triazolo[1,5-a]pyrimidin-7(4H)-one and eight novel 2,5-disubstituted [1,2,4]-triazolo[1,5-a]pyrimidine amine derivatives were synthesized based on the novel marine natural product Essramycin. Their anti-epileptic activities were evaluated by 4-aminopyridine (4-AP)-induced hyper excitability model in primary cultured neocortical neurons. Five compounds with [1,2,4]-triazolo[1,5-a]pyrimidin-7(4H)-one skeleton showed remarkable anti-epileptic activities. The preliminary structure-activity relationship (SAR) showed that the pyrimidine-7(4H)-one motif is the necessary "active core" of anti-epileptic activity. To understand the action mechanism of anti-epileptic activity of [1,2,4]-triazolo[1,5-a]pyrimidin-7(4H)-one compounds, docking studies using the model of GABAA as docking scaffolds were performed and the docking results were in concordance with the experiment observations. [Formula: see text].

The synthesis of analogs of shuangkangsu, a novel natural cycloperoxide glucoside from Lonicera japonica Thunb.

Four novel optically pure cycloperoxide glucosides 9a, 9b, 10a, and 10b, analogs of shuangkangsu--a natural product with unusual skeleton and antivirus activity from the buds of Lonicera japonica Thunb, were firstly synthesized by employing peroxidation and glucosidation reactions from phthalaldehyde or 4,5-dichloro phthalaldehyde and glucose.

The structure and absolute configuration of Shuangkangsu: a novel natural cyclic peroxide from Lonicera japonica (Thunb.).

A novel cyclic peroxide, shuangkangsu (1), has been obtained from the water extract of the buds of Lonicera japonica (Thunb.). The structure was elucidated as 5,8-divinyl-1,4-dihydro-1,4-di-O-beta-d-glucopyranosyl-2,3-dioxane (1) on the basis of the spectral data. Its absolute stereochemistry was determined to be (1S, 4S) by comparison of its CD curves with those of its optically pure analogs 2 and 3, which were synthesized from the phthalaldehyde. The absolute configurations of 2 and 3 were determined to be (1R, 4R) and (1S, 4S) by X-ray analysis and CD spectra, respectively. Compound 1 showed significant antiviral activities against influenza virus in chicken embryo and respiratory syncytial virus in cells.