 Linezolid is a completely synthetic drug : it does not occur in nature ( unlike erythromycin and many other antibiotics ) and was not developed by building upon a naturally occurring skeleton ( unlike most beta @-@ lactams , which are semisynthetic ) . Many approaches are available for oxazolidinone synthesis , and several routes for the synthesis of linezolid have been reported in the chemistry literature . Despite good yields , the original method ( developed by Upjohn for pilot plant @-@ scale production of linezolid and eperezolid ) is lengthy , requires the use of expensive chemicals — such as palladium on carbon and the highly sensitive reagents methanesulfonyl chloride and n @-@ butyllithium — and needs low @-@ temperature conditions . Much of the high cost of linezolid has been attributed to the expense of its synthesis . A somewhat more concise and cost @-@ effective route better suited to large @-@ scale production was patented by Upjohn in 1998 . 
