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