{HEAD ~ The compounds} are synthesized by reacting {TAIL ~ a compound} of the formula with an isocyanate of the formula under basic conditions in a non reactive, polar organic solvent 
{ HEAD ~ The compounds } are synthesized by reacting { TAIL ~ a compound } of the formula with an isocyanate of the formula under basic conditions in a non reactive , polar organic solvent
HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH