... 1466 Current Organic Chemistry, 2011, Vol. ... was also called p-nitroben- zenesulfonyloxyurethan (NBSU), p-nitrobenzenesulfonyloxycarba- mic acid ethyl ester, (ethoxycarbonylamino) 4-nitrobenzenesulfo- nate, N-ethoxycarbonyl-O-[(p-nitrophenyl)sulfonyl ... EtOCON3 72 °C ...