An excess of {HEAD ~ a tertiary amine}, e.g. diisopropylethylamine, N methylmorpholine, {TAIL ~ N methylpyrrolidine} or 4 DMAP is added to maintain the reaction mixture at a pH of about 8 
An excess of { HEAD ~ a tertiary amine } , e.g. diisopropylethylamine , N methylmorpholine , { TAIL ~ N methylpyrrolidine } or 4 DMAP is added to maintain the reaction mixture at a pH of about 8
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH