Synthesis and Antimicrobial Evaluation of Oxazole-2(3H)-thione and 2-Alkylsulfanyl-1,3-oxazole Derivatives

The preparation of oxazole-2(3H)-thiones (OXTs) by condensation of thiocyanic acid on α-hydroxycarbonyl substrates has been revisited. Extension to more complex scaffolds afforded chiral OXTs, whereas carbohydrate-fused 2-alkylsulfanyl-1,3-oxazolines led to original hemiaminal structures. A survey of the reactivity of OXTs with various electrophiles showed Sor N-chemoselectivity based on HSAB parameters. Antimicrobial evaluation of selected synthesized compounds was carried out, from which the hemiaminal 15 emerged as a promising antifungal agent. INTRODUCTION Treatment of infectious diseases still represents a topical challenge. The emergent infections as well as the increasing number of multi-drug resistant microbial pathogens specially Gram-positive bacteria have been a serious concern both in hospital and community settings. Linezolid (1) (ZyvoxTM) (Figure 1) is a member of the oxazolidinone drugs active against most Gram-positive pathogens, namely Staphylococcus aureus (MRSA) and Staphylococcus epidermis (MRSE). Although it has been approved HETEROCYCLES, Vol. 88, No. 2, 2014 1013