{HEAD ~ The base} can be, for example, {TAIL ~ pyridine}, dimethylaminopyridine, quinoline, trialkylamines, and mixtures thereof 
be
{ HEAD ~ The base } can be , for example , { TAIL ~ pyridine } , dimethylaminopyridine , quinoline , trialkylamines , and mixtures thereof
HEAD HEAD HEAD HEAD HEAD HEAD OTH REL OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH