Stereoselective synthesis and crystal structure of 4,6-O-benzylidene-N-octyl-D-allosamine hydrochloride

The building block of N-alkyl derivative of allosamidin（chitinase inhibitor）,4,6-O-benzylidene-N-octyl-D-allosamine hydrochloride was stereoselectively synthesized in two steps under mild conditions.Nucleophilic addition of octylamine to 2- oxoglucopyranoside gave a‘carbonyl group transfer＇ product in 62%yield.Subsequent stereoselective reduction of newly formed C=O with NaBH_4 produced title compound in 75%yield.X-ray diffraction analysis indicates the title compound adopts syn 1,2,3 stereochemistry and chair-chair conformation.The crystal structure is stabilized by hydrogen bonds.

Design,synthesis characterization and in vitro biological activity of a series of 3-aryl-6-(bromoarylmethyl)-7H-thiazolo[3,2-b]-1,2,4-triazin-7-one derivatives as the novel acetylcholinesterase inhibitors

Bromination is used as a strategy to improve biological activity in medicinal chemistry.In order to study on the structure-activity relationships of the novel acetylcholinesterase inhibitors with 7H-thiazolo[3,2-b]-1,2,4-triazin-7-one scaffold,based on our previous work and molecular modeling,a series of novel 3-aryl-6-（bromoarylrnethyl）-7H-thiazolo[3,2-b]-1,2,4-triazin-7-one derivatives were designed by molecular docking,synthesized and characterized by mass spectra,infrared spectra,proton NMR and elemental analyses.The study of AChE inhibitory activity was carried out using the Ellman colorimetric assay with huperzine-A as the positive control.Most of all target compounds exhibited more than 45%inhibition at 10μmol/L.The preliminary structureactivity relationship was the bromine atoms and the hydroxyl group at the phenyl ring at the C6 position of the parent nucleus played significant roles in the AChE inhibitory activity of the target compounds.