Application
Butyl isocyanate is the important raw material or intermediate that has widely applied in the synthesis of pharmaceutical, pesticide and dyestuff products, such as benzimidazole fungicides, sulfonylurea herbicides, and benomyl.
Butyl isocyanate is typical catalyst for the synthesis of the sulfonylurea herbicides, such as chlorsulfuron, sulfometuron, metsulfuron-methyl, and chlorimuron-ethyl, by treating the different groups substituted sulfonamide with phosgene in the presence of butyl isocyanate. Moreover, butyl isocyanate is also an intermedia for the synthesis of sulfonylurea.A number of novel sulfonylurea derivatives with sugar lowering activity, such as glibenclamide, tolbutamide, chlorpropamide and other hypoglycemic sulfonylurea agents also could be synthesized by using butyl isocyanate as synthetic intermediate.
Chemical Properties
Colorless, flammable liquid.
Chemical Properties
Colorless to faintly yellow liquid
Uses
n-Butyl isocyanate is used as an acylatingagent in the Friedel–Crafts reaction to produce amide.
Uses
Reagent in organic synthesis.
Definition
ChEBI: An isocyanate having a butyl group attached to the nitrogen.
Synthesis Reference(s)
The Journal of Organic Chemistry, 28, p. 2076, 1963
DOI: 10.1021/jo01043a030
General Description
A clear, colorless liquid with a pungent odor. Flash point 68°F. Very toxic by ingestion, and may also be toxic by skin absorption and inhalation. Vapors heavier than air. Less dense than water and insoluble in water. Produces toxic oxides of nitrogen during combustion.
Air & Water Reactions
Highly flammable. Extremely slow decomposition by water. Less dense than water and insoluble in water.
Reactivity Profile
Isocyanates and thioisocyanates 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. Base-catalysed reactions of isocyanates with alcohols should be carried out in inert solvents. Such reactions in the absence of solvents often occur with explosive violence [Wischmeyer 1969].
Hazard
Strong irritant to eyes and skin.
Health Hazard
n-Butyl isocyanate exhibits low inhalationtoxicity and relatively higher oral toxicity.This is in contrast to the aromatic isocyanates. The toxic effects are nausea, dyspnea, insomnia, coughing, and chest pain.Such symptoms, however, are much lessmarked than those of methyl isocyanate.
LC50 value, inhalation (mice): 680 mg/m
3LD50 value, oral (mice): 150 mg/kg
There is no report of any carcinogenic orteratogenic study of this compound.
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.
Flammability and Explosibility
Highly flammable
Safety Profile
A poison by ingestion
and intravenous routes. Mddly toxic by
inhalation. A powerful irritant to eyes, skin,
and mucous membranes. A flammable
liquid. See also CYANATES and
NITROGEN MONOXIDE.
Potential Exposure
N-Butyl isocyanate is used as a
reagent in organic synthesis; used as intermediates in production of pharmaceuticals, carbamate and urea insecticides, and fungicides. It is also used in the production of
sulfonylurea antidiabetic drugs
Shipping
UN2485 n-Butyl isocyanate, Hazard Class: 6.1;
Labels: 6.1—Poison Inhalation Hazard, 3—Flammable
liquid. Hazard, Inhalation Hazard Zone B. PGI.
Incompatibilities
Vapor 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 such as hydrides, urethanes,
ureas. Elevated temperatures or contact with acids, bases,
tertiary amines, and acylchlorides may cause explosive
polymerization. Contact with metals may evolve flammable
hydrogen gas. Attacks some plastics, rubber and coatings.
May accumulate static electrical charges, and may cause
ignition of its vapors
Waste Disposal
Dispose of contents and container to an approved waste disposal plant. Use a licensed
professional waste disposal service to dispose of this material. Caution: this chemical is highly flammable with a low
flash point (,20C). Dissolve or mix the material with a
combustible solvent and burn in a chemical incinerator
equipped with an afterburner and scrubber. All federal,
state, and local environmental regulations must be
observed.
