An attempt to prepare sulfonyl analogues of fotemustine: unexpected rearrangement to sulfamate during nitrosation step

A flexible strategy to access to dialkyl (((N-(2-chloroethyl)-N-sulfamoyl) amino) arylmethyl) phosphonates, as sulfonamidophosphonates precursors of Fotemustine analogues was developed. The last nitrosation step proceeded as a rearrangement to the non expected sulfonate analogues.