“…Particularly, triphenylphosphine (Ph 3 P) has been used along with carbon tetrachloride [8,23,24], carbon tetrabromide [25][26][27], diethyl azodicarboxylate [16], or bromine [7,28,29] in the synthesis of carbodiimides from N,N 0 -disubstituted ureas or thioureas. In several cases, triphenylphosphine dibromide has been used directly in the dehydration of a number of functionalized ureas [7,[30][31][32][33][34][35][36]. However, the reagent has to be freshly prepared and extra-dry conditions are required to achieve good conversion.…”