Method for producing 2-chloroallyl thiocyanate and 2-chloroallyl isothiocyanate

A process for producing 2-chloroallyl isothiocyanate of formula (II),

• comprising reacting 1,2,3-trichloropropane of formula (VI)
• with a base and then reacting resultant 2,3-dichloro-1-propene of formula (III)
• with a thiocyanate of formula (IV),
• M(SCN)n (IV),
• in which
• M is a metal cation or an ammonium group
• and
• n is from 1 to 4, as appropriate for a charge number of the cation,
• in the presence of a phase transfer catalyst of formula (V),
• in which moieties
• R1, R2, R3 and R4 are mutually independently hydrogen, C1-C24-alkyl, benzyl or C6-C10-aryl, the latter optionally substituted by halogen, C1-C6-alkyl, C1-C6-alkoxy, C1-C6-alkylamino, C1-C6-dialkylamino, hydroxy or phenyl
• and
• X is an anion,
• without diluent or in the presence of up to 15 percent by weight, based on 2,3-dichloropropene of formula (III) and simultaneously in the presence of an excess of from 10 to 200 mol percent of 2,3-dichloro-1-propene of formula (III) based on a thiocyanate of formula (IV).