View all references However, this general route to 1??azidoalkylphosphonates suffers from the use of highly toxic and explosive hydrazoic acid as the azide source. As an alternative to the Mitsunobu approach, Firouzabadi et al.1023. Firouzabadi , H. , Iranpoor , N. and Sobhani , S. 2004. PPh3/DDQ as a neutral system for the facile preparation of diethyl α??bromo, α??iodo and α??azidophosphonates from diethyl α??hydroxyphosphonates. Tetrahedron, 60: 203 [ ...