General description and application of Benzyl isocyanate

General description of Benzyl isocyanate:

Benzyl isocyanate [3173-56-6] or isocyanatomethylbenzene, Isocyanic Acid Benzyl Ester is a colorless to pale yellow liquid with the boiling point of 110-111°C at 40 mmHg.[1] This compound is highly toxic as other isocyanates and should be handled carefully. It is soluble in common organic solvents, and it hydrolyses in water therefore should be stored in a dry container.

Common preparation involves the use of highly toxic phosgene, which reacts with benzylamine.[2] Alternatively, it may be prepared from benzylbromide in a reaction with silver nitrocyanamide generated in situ [3] or by the pyrolysis of Nt-butylbenzyl-N-carbamoyl chloride.[4]

Application of Benzyl isocyanate:

Benzyl isocyanate is used as a protected ammonia equivalent in the stereoselective ring-opening of chiral 2,3-epoxy alcohols from Sharpless asymmetric epoxidation.[5] It was also used in a multicomponent, stereospecific synthesis of 1,3-oxazinane-2,4-diones catalysed with Al-salph complex.[6] Isocyanate can be used in preparation of disubstituted isocyanuric acid in reaction with KOCN.[1]

Product categorization (Chemical groups):

Main category:

Second level:

Third level:

Hazard Statements – Benzyl isocyanate:

H226 – Flammable liquid and vapour
H315 – Causes skin irritation
H317 – May cause an allergic skin reaction
H319 – Causes serious eye irritation
H334 – May cause allergy or asthma symptoms or breathing difficulties if inhaled
H335 – May cause respiratory irritation


[1] P.A. Argabright, B. L. Phillips, C. H. DePuy J. Org. Chem. 1970, 35, 2253.
[2] R. J. Slocombe, E. E. Hardy, J. H. Saunders, R. L. Jenkins J. Am. Chem. Soc. 1950, 72, 1888.
[3] J. H. Boyer, T. Manimaran, L. T. Wolford J. Chem. Soc., Perkin Trans. 1, 1988, 2137.
[4] J. N. Tilley, A. A. R. Sayigh J. Org. Chem. 1963, 28, 2076.
[5] W. R. Roush, M. A. Adam J. Org. Chem. 1985, 50, 3752.
[6] T. J. Church, Ch. M. Byrne, E. B. Lobkovsky, G. W. Coates J. Am. Chem. Soc. 2007 129, 8156.