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