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