Novel water soluble robust fluorescent coumarins substituted with oligomeric alkoxy functions were synthesized by incorporating the Blaise reaction in the key step. Mono- methylated oligomeric polyethylene glycols were subjected to a three step protocol, namely (i) Michael addition to acrylonitrile,(ii) Blaise reaction with ethyl bromoacetate and (iii) condensation with 4-N, N-diethylamino-2-hydroxybenzaldehyde to give fluorescent water ...
