68706-40-1 N-(p-Aminophenyl)-N'-((ethylamino)iminomethyl)-urea dihydrochloride Urea, 1-(p-aminophenyl)-3-ethylamino-, dihydrochloride Urea, N-(4-aminophenyl)-N'-((ethylamino)iminomethyl)-, dihydrochloride