Synthesis and characterisation of N-glycosyl amines from the reaction between 4,6-0-benzylidene-D-glucopyranose and substituted aromatic amines and also between 2-(o-aminophenyl)benzimidazole and pentoses or hexoses

Twelve N-glycosyl amines were synthesised using 4,6-O-benzylidene-D-glucopy ranose and different substituted aromatic amines, including some diamines t hat resulted in bis-glycosyl amines. Another set of six N-glycosyl amines w as synthesised using different hexoses and pentoses and 2-(o-aminophenyl)be nzimidazole. All compounds were isolated as solid products and purified, th eir elemental compositions were established, and these were characterised b y NMR (H-1 and C-13), UV-Vis, and FTIR spectroscopy, by FAB mass spectromet ry (molecular-ion peaks gave molecular weights), and by their optical rotat ions. While the protected saccharide, 4,6-O-benzylidene-D-glucopyranose, ex ists as a mixture of P and a anomers in solution, the corresponding N-glyco syl amines were of only the P anomeric form as determined by NMR and FTIR s pectroscopy. On the other hand, N-glycosyl amines synthesised from 2-(o-ami nophenyl)benzimidazole prefer the a anomeric form, and in two cases a mixtu re of both the P and the alpha anomers were observed. The trends observed i n the chemical shifts were compared among different products. (C) 2001 Else vier Science Ltd. All rights reserved.