Efficient preparation of secondary aminoalcohols through a Ti(IV) reductive amination procedure. Application to the synthesis and antibacterial evaluation of new 3 beta-N-[hydroxyalkyl]aminosteroid derivatives

摘要

An efficient method for the synthesis of various secondary aminoalcohols through a titanium(IV) isopropoxide-mediated reductive amination reaction of ketones is reported. Thus, different ketones gave the expected products in moderate to excellent yields up to 89% in numerous cases. A series of 3 beta-N-[hydroxyalkyl]aminosteroid derivatives were prepared according to this methodology and evaluated for their in vitro antimicrobial properties against human pathogens. All the compounds showed moderate to excellent activities against Gram-positive bacteria exhibiting similar results against Staphylococcus aureus and Streptococcus faecalis with Minimum Inhibitory Concentrations (MICs) varying from 3.12 to 25 mu g/mL. No significant antibacterial activities are encountered against Gram-negative bacteria. (c) 2008 Elsevier Ltd. All rights reserved.