Then 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 {HEAD ~ the equilibrium reaction} to {TAIL ~ completion} 
to
Then 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 { HEAD ~ the equilibrium reaction } to { TAIL ~ completion }
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 HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL