The one-pot transesterification of diethylarylvinylphosphonates with N-acetylcysteamine has been achieved using phosphonochloridates as intermediates. Reaction of phosphonodiesters with (COCl)(2) gave the corresponding chlorinated compounds, which were coupled with N-acetylcysteamine in presence of Et3N. (C) 2003 Published by Elsevier Science Ltd.