Phenyl isocyanate

Chemical properties

colourless to light yellow liquid with an acrid odour

Chemical properties

Phenyl isocyanate is a colorless liquid with an irritating odor.

The Uses of Phenyl isocyanate

Phenyl Isocyanate is also used in the synthesis of cyanopyridine derivatives in the search for anticancer compounds. It is also used in the synthesis of aminobenzimidazole derivatives with phenylcyclohexyl acetic groups showing antiobesity-antidiabetic activity.

The Uses of Phenyl isocyanate

Phenyl isocyanate was used to prepare chemically modified cellulose paper. It was used in the synthesis of functionalized graphene oxide nanoplatelets.

Definition

ChEBI: An isocyanate composed of a benzene ring bearing a single isocyanato substituent.

Preparation

To a mixture of aniline hydrochloride (12.95 g, 0.1 mol) and dry dioxane (100 mL) was added diphosgene (6.3 mL, 10.4 g, 0.05 mol). The mixture was heated to 60 °C; after stirring for 1.5 h, it became a clear solution. Heating was stopped after 3.5 h and the solvent was removed under reduced pressure. The residue was distilled at 70–73.5 °C (36 mmHg) to give 10.6 g (89%) of phenyl isocyanate. It could be redistilled almost quantitatively, bp 75–77 °C(39 mmHg) or 55–57 °C(16 mmHg).

Synthesis Reference(s)

Journal of the American Chemical Society, 90, p. 3295, 1968 DOI: 10.1021/ja01014a089

General Description

A colorless liquid. About the same density as water. Very toxic by ingestion, inhalation or skin absorption. Very irritating to skin, eyes and mucous membranes. Flash point 132°F.

Air & Water Reactions

Flammable. Decomposes in water.

Reactivity Profile

Isocyanates and thioisocyanates, such as Phenyl isocyanate, are incompatible with many classes of compounds, reacting exothermically to release toxic gases. Reactions with amines, aldehydes, alcohols, alkali metals, ketones, mercaptans, strong oxidizers, hydrides, phenols, and peroxides can cause vigorous releases of heat. Acids and bases initiate polymerization reactions in these materials. Some isocyanates react with water to form amines and liberate carbon dioxide. Polyurethanes are formed by the condensation reaction of diisocyanates with, for example, ethyl glycol. Phenyl isocyanate, cobalt pentamine triazo perchlorate, and nitrosyl perchlorate mixture was stirred for 2-3 minutes. When the stirring was interrupted, the mixture exploded [Chem. Eng. News 46(8):39. 1968].

Health Hazard

TOXIC; inhalation, ingestion or contact (skin, eyes) with vapors, dusts or substance may cause severe injury, burns or death. Bromoacetates and chloroacetates are extremely irritating/lachrymators. Reaction with water or moist air will release toxic, corrosive or flammable gases. Reaction with water may generate much heat that will increase the concentration of fumes in the air. Fire will produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution.

Fire Hazard

HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames. Vapors form explosive mixtures with air: indoors, outdoors and sewers explosion hazards. Most vapors are heavier than air. They will spread along ground and collect in low or confined areas (sewers, basements, tanks). Vapors may travel to source of ignition and flash back. Substance will react with water (some violently) releasing flammable, toxic or corrosive gases and runoff. Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated or if contaminated with water.

Safety Profile

A poison. An irritant. Mutation data reported. Flammable liquid when exposed to heat or flame; can react vigorously with oxidizing materials. Has exploded when stirred with (cobalt pentammine triazoperchlorate + nitrosyl perchlorate). When heated to decomposition it emits toxic fumes of CNand NOx. See also CYANATES.

Potential Exposure

Phenyl isocyanate is used as a laboratory reagent and in organic synthesis

Shipping

UN2487 Phenyl isocyanate, Hazard class: 6.1; Labels: 6.1-Poisonous materials, 3-Flammable liquid

Purification Methods

Distil phenylisocyanate under reduced pressure from P2O5. [Beilstein 12 IV 864.]

Incompatibilities

May form explosive mixture with air. Isocyanates are highly flammable and reactive with many compounds, even with themselves. Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explosions. Reaction with moist air, water or alcohols may form amines and insoluble polyureas and react exothermically, releasing toxic, corrosive or flammable gases, including carbon dioxide; and, at the same time, may generate a violent release of heat increasing the concentration of fumes in the air. Incompatible with amines, aldehydes, alkali metals, ammonia, carboxylic acids, caprolactum, alkaline materials, glycols, ketones, mercaptans, hydrides, organotin catalysts, phenols, strong acids, strong bases, strong reducing agents, urethanes, ureas. Elevated temperatures or contact with acids, bases, tertiary amines, and acyl-chlorides may cause explosive polymerization. Contact with metals may evolve flammable hydrogen gas. Attacks some plastics, rubber and coatings. Contact with metals may evolve flammable hydrogen gas. May accumulate static electrical charges, and may cause ignition of its vapors.