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