4-Chlorophenyl isothiocyanate
4-Chlorophenyl isothiocyanate (CAS: 2131-55-7, ClC6H4NCS) is a chemical reagent with a molecular weight of 169.63 g/mol. It serves as a crucial building block in organic synthesis and finds significant utility in biochemical research, particularly in protein sequencing and structural analysis. Its reactive nature makes it valuable for modifying proteins and other biomolecules, aiding in their characterisation and study.

Organic Synthesis
4-Chlorophenyl isothiocyanate is employed as a versatile intermediate and building block in the synthesis of various organic compounds. Its isothiocyanate group readily participates in reactions to form thioureas, heterocycles, and other derivatives.
Protein Sequencing
This compound is a key reagent in protein sequencing methodologies. It is used to derivatise N-terminal amino acids, facilitating their identification and sequencing through techniques such as Edman degradation.
Biochemical Research
In molecular biology and proteomics, 4-Chlorophenyl isothiocyanate aids in the structural analysis and characterisation of proteins and peptides. Its ability to react with specific functional groups on amino acids is exploited for labelling and modification studies.
| Molecular weight | 169.63 |
|---|---|
| Linear formula | ClC6H4NCS |
| Assay | ≥98.0% (AT) |
| Grade | purum |
| Boiling point | 135-136 °C/24 mmHg(lit.) |
| Melting point | 42-44 °C(lit.)43-45 °C |


Hazard statements
- H301Toxic if swallowed
- H311Toxic in contact with skin
- H315Causes skin irritation
- H317May cause an allergic skin reaction
- H319Causes serious eye irritation
- H331Toxic if inhaled
- H334May cause allergy or asthma symptoms if inhaled
- H335May cause respiratory irritation
Precautionary statements
- P261Avoid breathing dust, fume, gas or vapours
- P280Wear protective gloves, clothing and eye/face protection
- P301IF SWALLOWED
- P305IF IN EYES
- P311Call a POISON CENTER or doctor
| Protective equipment | Eyeshields, Faceshields, Gloves, type P2 (EN 143) respirator cartridges |
|---|---|
| Flash point | >113 °C / >235.4 °F |
| Transport (UN / ADR) | UN 2811 6.1 / PGII |
| Water hazard class (WGK, DE) | 3 |
| Hazard codes (EU) | T |
| Risk statements (R) | 23/24/25-36/37/38-42/43 |
| Safety statements (S) | 22-26-36/37-45 |
Hazard information is provided for guidance. Always consult the product Safety Data Sheet (SDS), available on request, before handling.
Documentation
Every batch ships with a Certificate of Analysis covering assay, identity and purity; the grade is confirmed against your enquiry. Safety Data Sheets and technical data sheets are available on request.
Supply & logistics
Samples for technical evaluation; bulk MOQ by grade and packaging. In-stock material ships in 7–10 working days, worldwide, with full export documentation.
What is 4-Chlorophenyl isothiocyanate used for?
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4-Chlorophenyl isothiocyanate is primarily used as a building block in organic synthesis and as a reagent in protein sequencing and biochemical research for protein structural analysis.
What are the CAS number and chemical formula for 4-Chlorophenyl isothiocyanate?
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The CAS number is 2131-55-7 and the chemical formula is ClC6H4NCS.
What grade and purity does Tech Serve Solutions supply?
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Tech Serve Solutions supplies 4-Chlorophenyl isothiocyanate in 'purum' grade with an assay of ≥98.0% (AT). We do not represent this product as USP, BP, or EP grade.
How should 4-Chlorophenyl isothiocyanate be handled safely?
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4-Chlorophenyl isothiocyanate is a dangerous substance that requires careful handling. It is toxic if swallowed, in contact with skin, or if inhaled, and can cause skin and eye irritation, allergic skin reactions, and respiratory irritation. Appropriate personal protective equipment, including eyeshields, face shields, gloves, and P2 respirator cartridges, must be used. Always consult the Safety Data Sheet (SDS) before handling.
How is 4-Chlorophenyl isothiocyanate packed and shipped?
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4-Chlorophenyl isothiocyanate is packed and shipped according to relevant transport regulations, designated as UN 2811, Class 6.1, Packing Group II. TSS is an experienced global supplier and exporter.
How can I request a quote or sample for 4-Chlorophenyl isothiocyanate?
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To request a quote or sample of 4-Chlorophenyl isothiocyanate, please contact the Tech Serve Solutions sales team through our website or by phone.
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