Methyl chloride boiling point

The major method for the production of methyl chloride (melting point -97.1°C, boiling point -24.2°C, density 0.9159) is by the reaction of methanol and hydrogen chloride, with the aid of a catalyst, in either the vapor or liquid phase. 

Dichloroacetic acid is produced in the laboratory by the reaction of chloral hydrate [302-17-0] with sodium cyanide (31). It has been manufactured by the chlorination of acetic and chloroacetic acids (32), reduction of trichloroacetic acid (33), hydrolysis of pentachloroethane [76-01-7] (34), and hydrolysis of dichloroacetyl chloride. Due to similar boiling points, the separation of dichloroacetic acid from chloroacetic acid is not practical by conventional distillation. However, this separation has been accompHshed by the addition of a eotropeforming hydrocarbons such as bromoben2ene (35) or by distillation of the methyl or ethyl ester. 

By-products from EDC pyrolysis typically include acetjiene, ethylene, methyl chloride, ethyl chloride, 1,3-butadiene, vinylacetylene, benzene, chloroprene, vinyUdene chloride, 1,1-dichloroethane, chloroform, carbon tetrachloride, 1,1,1-trichloroethane [71-55-6] and other chlorinated hydrocarbons (78). Most of these impurities remain with the unconverted EDC, and are subsequendy removed in EDC purification as light and heavy ends. The lightest compounds, ethylene and acetylene, are taken off with the HCl and end up in the oxychlorination reactor feed. The acetylene can be selectively hydrogenated to ethylene. The compounds that have boiling points near that of vinyl chloride, ie, methyl chloride and 1,3-butadiene, will codistiU with the vinyl chloride product. Chlorine or carbon tetrachloride addition to the pyrolysis reactor feed has been used to suppress methyl chloride formation, whereas 1,3-butadiene, which interferes with PVC polymerization, can be removed by treatment with chlorine or HCl, or by selective hydrogenation. 

A representative technical grade of methyl chloride contains not more than the following indicated quantities in ppm of impurities water, 100 acid, such as HCl, 10 methyl ether, 20 methanol, 50 acetone, 50 residue, 100. No free chlorine should be detectable. Traces of higher chlorides are generally present in methyl chloride produced by chlorination of methane. The boiling point should be between —24 and —23° C, and 5—95% should distill within a range of about 0.2°C. It should be clear, colorless, and free from visible impurities. 

Monomer and initiator must be soluble in the liquid and the solvent must have the desired chain-transfer characteristics, boiling point (above the temperature necessary to carry out the polymerization and low enough to allow for ready removal if the polymer is recovered by solvent evaporation). The presence of the solvent assists in heat removal and control (as it also does for suspension and emulsion polymerization systems). Polymer yield per reaction volume is lower than for bulk reactions. Also, solvent recovery and removal (from the polymer) is necessary. Many free radical and ionic polymerizations are carried out utilizing solution polymerization including water-soluble polymers prepared in aqueous solution (namely poly(acrylic acid), polyacrylamide, and poly(A-vinylpyrrolidinone). Polystyrene, poly(methyl methacrylate), poly(vinyl chloride), and polybutadiene are prepared from organic solution polymerizations. 

Other boiling points are 85.5-87°/13 mm. and 89-90°/15 mm. The use of as low a pressure as possible is advisable, since the substance tends to lose methyl chloride and form succinic anhydride. 

Low boiling isocyanates, such as methyl isocyanate [624-83-9], are difficult to prepare via conventional phosgenation due to the fact that the IV-alkyl carbamoyl chlorides are volatile below their decomposition point. Interestingly, N-ethyl carbamoyl chloride decomposes at its boiling point whereas the IV-propyl carbamoyl chloride is thermolyzed cleanly into isocyanate and hydrogen chloride. 

If bromoform is used, it is best to wash the fractions after filtration with a little methyl alcohol to dissolve the bromoform since the high boiling point of bromoform [151°C (304°F)] makes it difficult to remove completely by air drying. Furthermore, although it has been recommended that solutions of inorganic salts (e.g., calcium chloride, zinc chloride) in water may be used to replace the more expensive organic solvents, it is almost impossible to remove these salts from... 

The reactor needs to be kept clean to keep the heat transfer optimal and to prevent solid material in the prepolymer. The method employed is to use an appropriate solvent such as methyl ethyl ketone (MEK), methylene chloride, or m-pyrol (NMP). To prevent an explosive vapor mixture from being formed when the solvent is added to the reactor, the air must be replaced by nitrogen gas. The solvent needs to be heated to just above its boiling point and kept there until the solid material has been softened and removed from the metal. A second rinse with clean solvent may be needed. 

A solution of 11.9 parts of m-dimethylaminophenol in 90 parts of xylene (isomer mixture) is added to a solution of sodium methylate consisting of 2.0 parts of sodium and 25 parts of methanol. The methanol is then completely removed by distillation and the temperature raised until the boiling point of the xylene is reached. The decamethylene-bis-(N-methyl carbamic chloride) is added to the remainder which contains the sodium salt of m-... 

A mixture of the oily product (22 g), cuprous cyanide (10 g) and N-methyl-2-pyrrolidone (37 ml) in sealed tube was heated for 4.5 h at 140° to 150°C. After cooling, a solution of ferric chloride hexahydrate (44 g) and concentrated hydrochloric acid (11 ml) in water (60 ml) was added to the reaction mixture and then stirred at 50° to 60°C for 20 min. The reaction mixture was extracted with ether and the organic layer was washed with dilute aqueous hydrochloric acid, with water and with saturated saline solution successively, and dried over anhydrous sodium sulfate and then concentrated. The residue was purified by distillation under reduced pressure to give 3-methoxy-2,4,5-trifluorobenzonitrile (14.25 g) as colorless oil, boiling point 94°C/8 mm Hg. 

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