4,4'-Thiodianiline

4,4′-Thiodianiline (TDA) is the organosulfur compound with the formula (H2NC6H4)2S. It is classified as a diamine and a thioether. It typically appears as an (off-)white solid powder. An analogue of TDA is the drug dapsone, for which the sulphur species is oxidised.

4,4′-Thioaniline

Names
Preferred IUPAC name 4,4′-Sulfanediyldianiline
Other names p,p′-Thiodianiline; Bis(4-aminophenyl) sulfide; 4,4′-Thioaniline; 4-(4-Aminophenyl)sulfanylaniline
Identifiers
CAS Number	139-65-1 Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:82374 N
ChEMBL	ChEMBL348856 N
ChemSpider	8435 N
ECHA InfoCard	100.004.883
EC Number	205-370-9
KEGG	C19303 N
PubChem CID	8765
UNII	6GGU990BQF Y
CompTox Dashboard (EPA)	DTXSID9021344
InChI InChI=1S/C12H12N2S/c13-9-1-5-11(6-2-9)15-12-7-3-10(14)4-8-12/h1-8H,13-14H2 N Key: ICNFHJVPAJKPHW-UHFFFAOYSA-N N
SMILES C1=CC(=CC=C1N)SC2=CC=C(C=C2)N
Properties
Chemical formula	C12H12N2S
Molar mass	216.3 g/mol
Appearance	Brown-brown violet powder or needles
Density	1.26 g/cm3
Melting point	105 to 107 °C (221 to 225 °F; 378 to 380 K)
Boiling point	464.8 °C (868.6 °F; 738.0 K) @ 760mmHg
Hazards
Flash point	234.9 °C (454.8 °F; 508.0 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Synthesis

Sulfur is boiled in excess aniline over several hours to produce three isomers (1,1′; 1,4; 4,4′) of TDA.^[1] The same journal documents syntheses of similar and overlapping compounds by Merz and Weith in 1871, and K. A. Hoffman in 1894. A study by Nietzki and Bothof^[2] shows indications that including an oxide of lead may maximize the yield of the 4,4′ variant that this page refers to.

Uses

TDA was used as a chemical intermediate in the production of three dyes: CI mordant yellow 16, milling red G and milling red FR, as well as the medicine Dapsone. TDA has also been used in the synthesis of polyimine vitrimers.^[3]

Production

TDA is no longer produced in the USA.

Toxicity

TDA has caused mutations in some strains of Salmonella typhimurium and has caused tumors in laboratory mice and rats.

Related compounds

• 4,4'-Oxydianiline
• 4,4'-Methylenedianiline
• Dapsone