Typical angles for C-N=C and N=C=S linkages in aryl isothiocyanates are 165° and 177°, respectively. The N=C and C=S distances are 117 and 158 pms.
Synthesis and reactions
Isothiocyanates are generally prepared by the reaction of a primary amine (e.g. aniline) and carbon disulfide in aqueous ammonia. This combination results in precipitation of the solid ammonium dithiocarbamate salt, which is then treated with lead nitrate to yield the corresponding isothiocyanate.
Another method relies on a tosyl chloride mediated decomposition of dithiocarbamate salts that are generated in the first step above.
Isothiocyanates may also be accessed via the thermally-induced fragmentation reactions of 1,4,2-oxathiazoles. This synthetic methodology has been applied to a polymer-supported synthesis of isothiocyanates.
Reflecting their electrophilic character, isothiocyanates are susceptible to hydrolysis.
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