4-Isocyanatobenzoyl chloride
4-Isocyanatobenzoyl chloride (CAS: 3729-21-3) is an organic compound with the linear formula OCNC₆H₄COCl and a molecular weight of 181.58 g/mol. This chemical serves as a reactive intermediate, primarily utilised in organic synthesis for the introduction of isocyanatobenzoyl moieties into various molecules. It is a valuable building block in the development of pharmaceuticals, agrochemicals, and advanced materials.

Organic Synthesis Intermediate
Utilised as a bifunctional building block for the synthesis of complex organic molecules. Its reactive isocyanate and acid chloride groups allow for diverse chemical transformations.
Pharmaceutical Research
A key reagent in the development of novel pharmaceutical compounds, enabling the construction of diverse molecular scaffolds with potential therapeutic applications.
Materials Science
Employed in the creation of specialised polymers and advanced materials where its unique functional groups can be incorporated to tailor material properties.
| Molecular weight | 181.58 |
|---|---|
| Linear formula | OCNC6H4COCl |
| Assay | 98% |
| Boiling point | 54-55 °C/0.07 mmHg(lit.) |
| Density | 1.317 g/mL at 25 °C(lit.) |
| Melting point | 36-38 °C(lit.) |


Hazard statements
- H302Harmful if swallowed
- H312Harmful in contact with skin
- H314Causes severe skin burns and eye damage
- H317May cause an allergic skin reaction
- H332Harmful if inhaled
- H335May cause respiratory irritation
Precautionary statements
- P261Avoid breathing dust, fume, gas or vapours
- P280Wear protective gloves, clothing and eye/face protection
- P305IF IN EYES
- P310Immediately call a POISON CENTER or doctor
| Protective equipment | Eyeshields, Faceshields, full-face particle respirator type N100 (US), Gloves, respirator cartridge type N100 (US), type P1 (EN143) respirator filter, type P3 (EN 143) respirator cartridges |
|---|---|
| Flash point | 113 °C / 235.4 °F |
| Transport (UN / ADR) | UN 3261 8 / PGII |
| Water hazard class (WGK, DE) | 3 |
| Hazard codes (EU) | C |
| Risk statements (R) | 20/21/22-34-36/37-42/43 |
| Safety statements (S) | 26-27-28-36/37/39-45 |
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-Isocyanatobenzoyl chloride used for?
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4-Isocyanatobenzoyl chloride is primarily used as a reactive intermediate in organic synthesis for creating more complex molecules, particularly in pharmaceutical research and materials science.
What are the CAS number and formula for 4-Isocyanatobenzoyl chloride?
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The CAS number is 3729-21-3 and the linear formula is OCNC₆H₄COCl.
What grade and purity does Tech Serve Solutions supply for 4-Isocyanatobenzoyl chloride?
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Tech Serve Solutions supplies 4-Isocyanatobenzoyl chloride with an assay of 98%. This is a technical grade, and we do not represent it as meeting USP, BP, or EP pharmacopoeia standards.
How should 4-Isocyanatobenzoyl chloride be handled?
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4-Isocyanatobenzoyl chloride is a dangerous substance. It is harmful if swallowed, in contact with skin, or if inhaled, causes severe skin burns and eye damage, and may cause an allergic skin reaction and respiratory irritation. Handle with extreme caution using appropriate personal protective equipment including gloves, eye protection, and respiratory protection in a well-ventilated area. Refer to the safety data sheet for full details.
How is 4-Isocyanatobenzoyl chloride packaged and exported?
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4-Isocyanatobenzoyl chloride is carefully packaged to ensure safety during transit and is available for global export by Tech Serve Solutions.
How can I request a quote or sample of 4-Isocyanatobenzoyl chloride?
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To request a quote or sample, please contact our sales team through the TSS website, providing your contact details and the product information.
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