Thiocarbanilide
[CAS# 102-08-9]

Identification

• Classification: Chemical reagent >> Organic reagent >> Thiourea
• Name: Thiocarbanilide
• Synonyms: N,N'-Diphenylthiourea; sym-Diphenylthiourea; 1,3-Diphenyl-2-thiourea
• Molecular Formula: C₁₃H₁₂N₂S
• Molecular Weight: 228.31
• CAS Registry Number: 102-08-9
• EC Number: 203-004-2
• SMILES: C1=CC=C(C=C1)NC(=S)NC2=CC=CC=C2

Properties

• Density: 1.3±0.1 g/cm³ Calc.^*, 1.32 g/mL (Expl.)
• Melting point: 152 - 155 ºC (Expl.)
• Boiling point: 348.7±25.0 ºC 760 mmHg (Calc.)^*
• Flash point: 164.7±23.2 ºC (Calc.)^*
• Index of refraction: 1.749 (Calc.)^*
• Water solubility: <0.01 g/100 mL at 19 ºC

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS06;GHS07;GHS08;GHS09 Danger
• Hazard Statements: H300-H317-H361-H373-H411
• Precautionary Statements: P203-P260-P261-P264-P270-P272-P273-P280-P301+P316-P302+P352-P318-P319-P321-P330-P333+P317-P362+P364-P391-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Specific target organ toxicity - repeated exposure	STOT RE	2	H373
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411
Skin sensitization	Skin Sens.	1A	H317
Reproductive toxicity	Repr.	2	H361d
Skin sensitization	Skin Sens.	1	H317
Reproductive toxicity	Repr.	2	H361
Acute toxicity	Acute Tox.	2	H300
Acute toxicity	Acute Tox.	2	H301
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Specific target organ toxicity - single exposure	STOT SE	3	H335
Skin irritation	Skin Irrit.	2	H315
Eye irritation	Eye Irrit.	2	H319

• Transport Information: UN 2811

Discovory and Applicatios

Thiocarbanilide, also known as diphenylthiourea, is an organosulfur compound with the chemical formula (C₆H₅)₂NC(S)NH₂. It consists of two phenyl groups attached to a thiourea core, where the oxygen atom of urea is replaced by sulfur. Thiocarbanilide appears as a white crystalline solid and is characterized by its moderate solubility in organic solvents.

The compound was first synthesized in the 19th century as part of studies on thioureas and their derivatives. Its structure and chemical properties have been extensively investigated, revealing typical thiourea behavior with a strong sulfur presence in the functional group.

Thiocarbanilide is mainly used in the rubber industry as a vulcanization accelerator. It acts to increase the efficiency of sulfur cross-linking during rubber curing, thereby enhancing the mechanical properties and elasticity of rubber products. By accelerating vulcanization, thiocarbanilide reduces curing time and improves overall production efficiency.

Beyond its role in rubber processing, thiocarbanilide serves as an intermediate in organic synthesis. It is employed in the preparation of various sulfur-containing heterocyclic compounds and pharmaceuticals. The presence of both sulfur and amino groups in its structure allows it to participate in diverse chemical reactions, including nucleophilic substitution and condensation reactions.

Thiocarbanilide also finds applications as a stabilizer and additive in polymer chemistry, contributing to improved thermal stability and resistance to degradation in certain plastics.

Due to its chemical nature, thiocarbanilide must be handled with care, as exposure to dust or prolonged contact may cause irritation. It is generally considered to have low toxicity when used according to safety guidelines.

Physically, thiocarbanilide melts at around 180–182 °C and is stable under normal laboratory conditions. It can be synthesized by the reaction of aniline with carbon disulfide and subsequent treatment with ammonium derivatives or by direct thiation of urea derivatives.

In summary, thiocarbanilide’s discovery and use have been primarily centered around its role as a vulcanization accelerator in rubber manufacturing and as a versatile intermediate in chemical synthesis. Its functional properties continue to support applications in polymer and materials science, contributing to the production of improved elastomers and specialty chemicals.

References

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DOI: 10.1007/bf01523636

2019. Cyclization of Activated Methylene Isocyanides with Methyl N(N),N'-Di(tri)substituted Carbamimidothioate: A Novel Entry for the Synthesis of N,1-Aryl-4-tosyl/ethoxycarbonyl-1H-imidazol-5-amines. SynOpen, 3(3).
DOI: 10.1055/s-0039-1690328

2021. Palladium-Catalyzed Desulfurative Hiyama Coupling of Thioureas to Achieve Amides via Selective C�N Bond Cleavage. Synthesis, 53(20).
DOI: 10.1055/s-0040-1720907