Phosgene highly toxic

COCl2 -118 8 Phosgene highly toxic used in the manufacture of polyurethane plastics... 

Waste Disposal. Because of its low Boiling poiat and high, toxicity, measures must be taken to prevent the entrance of phosgene iato drains or sewers. If recycle of phosgene is not feasible, phosgene waste can be handled by one of the decomposition methods mentioned above, ie, caustic scmbbiag, moist activated carbon towers, or combustion. 

Phosgene [75-44-5] M 98.9, b 8.2 /756mm. Dried with Linde 4A molecular sieves, degassed and distilled under vacuum. This should be done in a closed system such as a vacuum line. HIGHLY TOXIC, should not be inhaled. If it is inhaled operator should lie still and made to breath ammonia vapour which reacts with phosgene to give urea. 

Thermal degradation in contact with flame or red hot surfaces will produce highly-toxic gases, e.g. acid chlorides and phosgene. Reaction with freshly-galvanized surfaces may produce dichloroacetylene, which is also highly toxic. 

Self-Test 13.4B The highly toxic gas carbonyl chloride, COCl2 (phosgene), is used to synthesize many organic compounds. Use the following data to write the rate law and determine the value of k for the reaction used to produce carbonyl chloride ... 

Caution Phosgene is highly toxic. This preparation should be carried out in a well-ventilated hood. 

Caution Phosgene is highly toxic. Part B should be performed in an efficient hood. For a warning regarding the use of benzene, see ref. 2. 

M-NHC catalysts in this area. Metal catalysed carbonylation also provides an alternative synthetic ronte to the prodnction of materials that traditionally reqnire highly toxic precnrsors, like phosgene. This section discnsses carbonylation of aryl hahdes, oxidative carbonylation of phenolic and amino componnds, carbonylation of aryl diazoninm ions, alcohol carbonylation, carbonylative amidation, and copolymerisation of ethylene and CO. 

Highly toxic perfluoroisobutylene (PFIB) poses a serious health hazard to the human respiratory tract. PFIB is a thermal decomposition of polytetrafluo-roethylene (PTFE), e.g., Teflon. PFIB is approximately lOx as toxic as phosgene. Inhalation of this gas can cause pulmonary edema, which can lead to death. PFIB is included in Schedule 2 of the Chemical Weapons Convention (CWC), the aim of the inclusion of chemicals such as PFIB was to cover those chemicals, which would pose a high risk to the CWC. 

Most of the materials used in the manufacture of chemicals are poisonous, to some extent. The potential hazard will depend on the inherent toxicity of the material and the frequency and duration of any exposure. It is usual to distinguish between the short-term effects (acute) and the long-term effects (chronic). A highly toxic material that causes immediate injury, such as phosgene or chlorine, would be classified as a safety hazard. Whereas a material whose effect was only apparent after long exposure at low concentrations, for instance, carcinogenic materials, such as vinyl chloride, would be classified as industrial... 

Preparation of SC-PEG. Warning Synthesis of this reagent involves the use of phosgene, a highly toxic substance. All manipulations should therefore be performed in a well-ventilated hood. 

Trichloromethyl chloroformate (diphosgene) is used as a safe substitute for highly toxic phosgene gas. The latter is generated in situ by addition of catalytic amounts of tertiary amines or amides, or active carbon. Diphosgene also disproportionates to 2 equivalents of phosgene on heating above 250°C. 

A modification of Zalipsky s method by Miron and Wilchek (1993) simplifies the creation of the SC-activated species. Instead of using highly toxic phosgene to form a chloroformate intermediate and then reacting with NHS, the new procedure utilizes either N-hydroxysuccinimidyl chloroformate or N,N -disuccinimidyl carbonate (DSC Chapter 4, Section 1.7) to produce the SC-PEG in one step (Figure 25.6). Since both activation reagents are commercially available, creating an amine-reactive PEG derivative has never been easier. 

Phosgene, COCI2, is a highly toxic gas that is heavier than air. It can he produced hy reacting carhon monoxide with chlorine in a very slow reaction. 

Conversion of 2 to the highly crystalline oxazolidinone 3 with phosgene has been described by Thornton who has employed this substance as a chiral auxiliary in asymmetric aldol reactions of its N-propionyl derivative. Kelly has also used an oxazoline derived from 3 as a chiral auxiliary in asymmetric alkylation of a glycolate enolate. Oxazolidinone 3 has also been prepared from 2 with diethyl carbonate in the presence of potassium carbonate. The conversion of 2 to the oxazolidinone 3 is accomplished using triphosgene in this procedure because of the high toxicity of phosgene. 

Phosgene is a highly toxic gas. All safety precautions must he followed during its preparation and handling. It is stored and shipped in leak-free steel cylinders in the complete absence of any water (or moisture). 

The traditional method of making polycarbonate is environmentally dubious, however, for two reasons. First, one of the starting materials, phosgene, is a highly toxic compound. Second, the catalyst used in... 

Phosgene is highly toxic gas (caution ). Phosgene is a suitable reagent for this method since it can simultaneously activate several functional groups such as amines, carboxylic acids, hydroxyl, etc. Twenty percent of COCl in toluene, almost saturated solution, is commercial available from Aldrich ( 681776). 

Caution. Phosgene is a highly toxic gas that reacts with water to form HCl and has a characteristic odor of freshly mown hay. It is necessary to carry out this portion of the reaction using standard Schlenk techniques and in a well-ventilated fume hood. Unreacted phosgene can be neutralized with aqueous base. 

Caution. Because phosgene is volatile (bp 8°C) and highly toxic by inhalation or skin contact, is a severe lachrymator and is moisture-sensitive, this reaction should be performed in a well-ventilated hood. See general comments for choosing phosgene or related reagents elsewhere in this volume. 

Caution. CO gas and phosgene (which may be formed as a volatile byproduct in the first step) are highly toxic. Appropriate personal protection must be adopted and all manipulations must be carried out in a highly efficient fume hood. 

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