Then {HEAD ~ the orthoester} is converted in high yields to the corresponding imidic ester by condensation with an aniline while simultaneously removing alkanol from the reaction mixture to drive the equilibrium reaction to {TAIL ~ completion} 
Then { HEAD ~ the orthoester } is converted in high yields to the corresponding imidic ester by condensation with an aniline while simultaneously removing alkanol from the reaction mixture to drive the equilibrium reaction to { TAIL ~ completion }
OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL