Article No : a06_233
Chloromethanes
MANFRED ROSSBERG, Hoechst Aktiengesellschaft, Frankfurt/Main, Germany
WILHELM LENDLE, Hoechst Aktiengesellschaft, Frankfurt/Main, Germany
GERHARD PFLEIDERER, Hoechst Aktiengesellschaft, Frankfurt/Main, Germany
ADOLF TO¨ GEL, Hoechst Aktiengesellschaft, Frankfurt/Main, Germany
THEODORE R. TORKELSON, Dow Chemical, Midland, Michigan, United States 48674
KLAUS K. BEUTEL, Dow Chemical Europe, Horgen, Switzerland
1. Introduction...... 15 5.2. Analysis ...... 33 2. Physical Properties ...... 16 6. Storage, Transport, and Handling ...... 34 3. Chemical Properties ...... 19 7. Behavior of Chloromethanes 4. Production ...... 20 in the Environment ...... 35 4.1. Theoretical Bases...... 20 7.1. Presence in the Atmosphere...... 35 4.2. Production of Monochloromethane ...... 23 7.2. Presence in Water Sources ...... 36 4.3. Production of Dichloromethane and 8. Uses and Economic Aspects ...... 36 Trichloromethane ...... 25 9. Toxicology ...... 37 4.4. Production of Tetrachloromethane ...... 29 References ...... 39 5. Quality Specifications...... 33 5.1. Purity of the Commercial Products and their Stabilization...... 33
1. Introduction methyl chloride by the chlorination of methane occurred before World War I, with the intent of Among the halogenated hydrocarbons, the chlo- hydrolyzing it to methanol. A commercial meth- rine derivatives of methane monochloromethane ane chlorination facility was first put into opera- (methyl chloride) [74-87-3], dichloromethane tion by the former Farbwerke Hoechst in 1923. In (methylene chloride) [75-09-2], trichloro- the meantime, however, a high-pressure metha- methane (chloroform) [67-66-3], and tetrachlor- nol synthesis based on carbon monoxide and omethane (carbon tetrachloride) [56-23-5] play hydrogen had been developed, as a result of an important role from both industrial and eco- which the opposite process became practical – nomic standpoints. These products find broad synthesis of methyl chloride from methanol. application not only as important chemical inter- mediates, but also as solvents. Dichloromethane was prepared for the first time in 1840 by V. REGNAULT, who successfully Historical Development. Monochloro- chlorinated methyl chloride. It was for a time methane was produced for the first time in produced by the reduction of trichloromethane 1835 by J. DUMAS and E. PELIGOT by the reaction (chloroform) with zinc and hydrochloric acid in of sodium chloride with methanol in the presence alcohol, but the compound first acquired signifi- of sulfuric acid. M. BERTHELOT isolated it in 1858 cance as a solvent after it was successfully pre- from the chlorination of marsh gas (methane), as pared commercially by chlorination of methane did C. GROVES in 1874 from the reaction of and monochloromethane (Hoechst AG, Dow hydrogen chloride with methanol in the presence Chemical Co., and Stauffer Chemical Co.). of zinc chloride. For a time, monochloromethane Trichloromethane was synthesized indepen- was produced commercially from betaine hydro- dently by two groups in 1831: J. VON LIEBIG chloride obtained in the course of beet sugar successfully carried out the alkaline cleavage of manufacture. The earliest attempts to produce chloral, whereas M. E. SOUBEIRAIN obtained the