Phenylisothiocyanate

Phenylisothiocyanate (PITC) is an organic compound used in the chemical synthesis of various pharmaceuticals and is a derivative of isothiocyanate. It is a colorless liquid, although commercial samples can appear colored.

Structure and reactivity

Phenylisothiocyanate is a simple aromatic isothiocyanate. It features a phenyl group (C6H5-) attached to an isothiocyanate functional group (-N=C=S). The molecule is planar. The C=N=C=S backbone is linear, consistent with the multiple bonding in this part of the molecule.

Synthesis

Phenylisothiocyanate is produced by the reaction of aniline with carbon disulfide in the presence of a base, typically ammonia. This reaction is a variant of the Willgerodt-Kindler reaction.

Applications

Phenylisothiocyanate is used in the Edman degradation, a method used in protein sequencing. This application exploits the fact that PITC reacts with the amino group in amino acids to form a phenylthiocarbamyl derivative.

Safety

Phenylisothiocyanate is a lachrymator and is harmful if swallowed, inhaled, or in contact with the skin. It is also classified as a potential carcinogen.

See also

• Isothiocyanate
• Edman degradation
• Willgerodt-Kindler reaction