Phenyl isocyanate

Description

Phenyl isocyanate

Phenyl isocyanate is an organIC compound containing a benzene ring attached to an isocyanate group (–N=C=O). It is commonly used as a building block in organic synthesis and polymer chemistry.

Formula and structure

• Molecular formula: C7H5NO
• Molecular weight: ~119.12 g/mol
• Structure: A benzene ring (C6H5) with an isocyanate group attached to one carbon, giving the functional group Ph–N=C=O.

Key properties (qualitative)

• Appearance: Colorless to pale yellow liquid
• Odor: Sharp and irritating
• Reactivity: The isocyanate group is highly reactive with nucleophiles such as amines and water
• Hydrolysis: Reacts with water to yield aniline (phenylamine) and carbon dioxide
  • Ph–N=C=O + H2O → Ph–NH2 + CO2
• Stability: Reactive with moisture; typically stored under dry, inert conditions

Reactions you should know

• With amines (to form ureas):
  Ph–N=C=O + RNH2 → Ph–NH–CO–NR (primary amines give N,N-disubstituted ureas, secondary amines give mono-substituted ureas)
• With water (hydrolysis):
  Ph–N=C=O + H2O → Ph–NH2 + CO2
• With alcohols (to form carbamates):
  Ph–N=C=O + ROH → Ph–NH–COOR

Common uses

• Building block for polyurethanes and polyurea materials
• Reagent for introducing the phenyl isocyanate moiety in organic synthesis
• Intermediary in the preparation of carbamates and ureas for pharmaceuticals and dyes

Synthesis and preparation (general approaches)

• Phosgenation of aniline derivatives: Aniline derivatives can be converted to aryl isocyanates by reacting with phosgene or phosgene equivalents under controlled conditions.
• Dehydration routes: Aryl carbamates can be dehydrated to give the corresponding aryl isocyanate.
• Note: The exact industrial method depends on scale, availability of starting materials, and safety considerations.

Handling and safety

• Hazards: Corrosive and irritating to skin, eyes, and respiratory tract; reacts with moisture
• Storage: Store in a tightly closed container, in a cool, dry, well-ventilated area away from moisture and oxidizers
• Personal protective equipment: Use appropriate gloves, goggles, and ventilation; handle in a fume hood
• First aid (quick guidance): In case of skin/eye contact, rinse with plenty of water; if inhaled, move to fresh air and seek medical attention; if ingested, do not induce vomiting and seek medical advice
• Environmental note: Avoid release to the environment; handle waste according to local regulations

Quick takeaway

• Phenyl isocyanate (Ph–N=C=O) is a reactive aryl isocyanate used to make ureas, carbamates, and polyurethane materials. It readily undergoes hydrolysis to aniline and reacts with amines to form ureas. Handle with care under proper ventilation and moisture-free conditions.

If you’d like, I can add a short reaction diagram or provide a practical preparation/example synthesis using a specific starting material.