NpPS is a compound related to Lawessons reagent formed by the reaction of 1-bromonaphthalene with PS, this is a 1,3,2,4-dithiadiphosphetane 2,4-disulfide which has a naphth-1,8-diyl group holding the two phosphorus atoms together. The mechanism by which the NpPS forms is not yet elucidated, but it is thought to occur by a process involving free radicals, and naphthalene has been detected as a side product in its synthesis. In general, NpPS has been found to be less reactive than Lawessons reagent, in agreement with the hypothesis that the dithiophosphine ylides are responsible for the majority of the chemical reactions of the 1,3,2,4-dithiadiphosphetane 2,4-disulfides.
NpPS has been found to react with many hydroxyl compounds, such as methanol, ethylene glycol and a catechol to form species with oxygen atoms bonded to the phosphorus atoms.
NpPS when refluxed in methanol reacts to form a heterocycle CHOPS with one O-methyl and one S-methyl bonded to the two phosphorus atoms.