Isocyanates, organic methyl isocyanate

Many organic chemicals are analyzed by RPC. These include various arylhydroxylamines as the N-hydroxyurea derivative with methyl isocyanate (614) alkyl- and alkoxy-disubstituted azoxybenzenes (6t5), n-alkyl-4-nitrophenylcarbonate esters ranging in length from methyl to octyl (616), 4-nitrophenol in the presence of 4-nitrophenyl phosphate (617), ben-zilic acid, and benactyzine-HCI using ion-pair chromatography (618), as well as aniline and its various metabolites (619), stereoisomers of 4,4 -dihydroxyhydrobenzoin (620), and aldehydes and ketones as the 2,4-dinitrophenylhydrazones (621). The technique has also been used to analyze propellants and hydrazine and 1,1-dimethylhydrazine were quantitita-vely determined (622, 623). 

Synonyms isocyanic acid methyl ester, isocyanatomethane, MIC Formula CH3NCO MW 57.05 CAS [624-83-9] used in the manufacture of carbamate pesticides colorless liquid with an unpleasant odor boils at 39°C freezes at -80°C vapor pressure 400 torr at 20°C density 0.96 g/mL at 20°C vapor density 1.97 (air= 1) decomposes in water soluble in most organic solvents highly toxic and flammable. 

Methyl isocyanate and all isocyanic acid esters are an interesting and highly reactive class of organic compounds, since the isocyanate group (-NC0) reacts readily with a wide variety of compounds as well as with itself to form dimers, trimers, ureas, and carbodi-imides. Methyl isocyanate (MIC) is an intermediate in the preparation of carbamate pesticides and conceivably could be applied to the production of special heterocyclic polymers and derivatives. 

Dwivedi, P.D., Mishra, A., Gupta, G.S.D., Dutta, K.K., Das, S.N., Ray, P.K. (1988). Inhalation toxicity studies of methyl isocyanate (MIC) in rats. IV. Immunologic response of rats one week after exposure effect on hody and organ weights, phagoc dic and DTH response. Indian J. Exp. Biol. 26 191. ... 

Methyl isocyanate (MIC) is used as an intermediate in organic synthesis, especially in the production of carbamate based pesticides. It is also used to produce polyurethane foams and plastics. Occasionally, it is present in cigarette smoke in very minute quantities. 

In 1984, a deadly cloud of methyl isocyanate killed thousands of people in Bhopal, India. Shortly thereafter, there was a serious chemical release at a sister plant in West Virginia. These incidents underscored demands by industrial workers and communities in several states for information on hazardous materials. Public interest and environmental organizations around the United States accelerated demands for information on toxic chemicals being released to the environment. Against this backdrop, the Emergency Planning and Community Right-to-Know Act (EPCRA) was enacted in 1986. 

A mixture of 1 -(hydroxyamino)-2,3-diphenylcyclopropenylium chloride (0.52 g, 2.0 mmol), methyl isocyanate (0.23 g, 4.0 mmol) and EtjN (0.40 g, 4.0 mmol) in CH2CI2 (15 mL) was vigorously stirred at 20°C for 1 d. The resulting solution was poured into cold HjO and the organic layer was separated. The aq layer was extracted with CHjClj, the combined extracts were dried (Na2COj) and evaporated, and the residue was recrystallized (EtjO/petroleum ether) yield 0.50g (75%) mp 135- 137"C. 

FERMC(III) SULFATE (10028-22-5) Fej(S04)3 Light sensitive. Hygroscopic hydrolyzed slowly in water , forming acid solution and precipitates hydroxide and phosphate salts. Violent reaction with strong bases. Aqueous solution (often shipped as 73% solution) is incompatible with sulfiiric acid, aluminum, caustics, alkylene oxides, ammonia, aliphatic amines, alkanolamines, amides, epichlorohydrin, organic anhydrides, isocyanates, magnesium, methyl isocyanoacetate, vinyl acetate. Corrosive to copper, copper alloys, and both mild and galvanized steel. 

METHYL DICHLOROETHANOATE (116-54-1) C3H4CI2O2 Combustible, water-reactive liquid (flash point 176°F/80°C). Contact with water causes heat and decomposition to corrosive dichloroacetic acid. Aqueous solution is an acid. Incompatible with sulfuric acid, alkalis, ammonia, aliphatic amines, alkanolamines, alkylene oxides, amides, epichlorohydrin, organic anhydrides, isocyanates, vinyl acetate. Strong oxidizers may cause fire and explosions. Attacks metals in the presence of moisture. Thermal decomposition releases toxic phosgene and HCl gases. 

---