title: Naphthalen-1,8-diyl 1,3,2,4-dithiadiphosphetane 2,4-disulfide
text: # Naphthalen-1,8-diyl 1,3,2,4-dithiadiphosphetane 2,4-disulfide
  
  $NpP_2S_4$ is a compound related to Lawesson's reagent formed by the reaction of 1-bromonaphthalene with $P_4S_{10},$ 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 $NpP_2S_4$ 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, $NpP_2S_4$ has been found to be less reactive than Lawesson's 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.
  
  $NpP_2S_4$ 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.
  
  $NpP_2S_4$ when refluxed in methanol reacts to form a heterocycle $C_{12}H_{12}OP_2S$ with one O-methyl and one S-methyl bonded to the two phosphorus atoms.
  
  | The structure of the product of methanol and $NpP_2S_4$ | The structure of the first product of $NpP_2S_4$ with ethylene glycol | The structure of the product of di-tert-butylcatechol with $NpP_2S_4$ |
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