The Herz reaction, named after the chemist
Richard Herz, is the chemical conversion of an
aniline to the benzo
dithiazolium salt by its reaction with
disulfur dichloride. The salt is called a Herz salt.
Hydrolysis of this Herz salt give the corresponding
sodium thiolate, which can be further converted to the 2-aminothiophenol.[1]
The 2-aminothiophenols are suitable for diazotization, giving benzothiadiazoles.[2] Instead the sodium 2-aminothiophenolate can be converted to a 1,3-
benzothiazole.
Dyes
Aniline 5 is converted to compound 6, in three steps;
conversion to an ortho-
aminothiol through the Herz-reaction (aniline 5 and disulfur dichloride), followed by
conversion to an ortho-aminoarylthioglycolacid and
^W. K. Warburton (1957). "Arylthiazathiolium Salts And o-Aminoaryl Thiols - The Herz Reaction". Chemical Reviews. 57 (5): 1011–1020.
doi:
10.1021/cr50017a004.
^Kirby, P.; Soloway, S. B.; Davies, J. H.; Webb, Shirley B. (1970). "1,2,3-Benzothiadiazoles. Part I. A simplified synthesis of 1,2,3-benzothiadiazoles". Journal of the Chemical Society C: Organic (16): 2250.
doi:
10.1039/J39700002250.