Preparation of trifluoromethane
Trifluoromethane is prepared by reacting iodoform with mercury (I) fluoride.
The mixture of iodoform, mercury (I) fluoride and powder of mineral fluorite (also called fluorspar (CaF2) as a diluent) in proportion 20: 33.4: 40 triturated and placed in a 100 ml glass flask. From the flask gas outlet is connected with the collector which is immersed in liquid nitrogen and protected from moisture with phosphorus pentoxide.
The flask is heated on a silicon oil bath. At ~ 80 °C reaction begins. Further, the temperature rises to ~ 150 °C by itself. The trifluoromethane collects in the trap. After the reaction is complete and no new portions of trifluoromethane is formed the product is purified by distillation and collection of fraction with boiling point -40 -30 °C. Further trifluoromethane is washed with 2N sodium hydroxide solution and dried over phosphorus pentoxide. The yield of is trifluoromethane 45%.
Trifluoromethane could also be is prepared by reacting chloroform with hydrogen fluoride.
To the autoclave made of special steal, which is connected to the stirrer and reflux condenser 360 g of chloroform and 600 g of antimony pentachloride (SbCl5) (as catalyst) are placed. To this autoclave 200 g of anhydrous hydrogen fluoride is introduced and reaction mixture is heated 1.5 hours at 130° C. The pressure of autoclave reaches 77 bar and slowly is released by collecting outgoing gas. The trifluoromethane is washed with ice-cold solution of diluted sodium hydroxide and dried over phosphorus pentachloride. Trifluoromethane is purified by distillation. The yield of final product is 95%. Antimony pentachloride as a catalyst could be re-used many times. The obtained product is colorless gas. melting point -160° C; boiling point – 84.4° C. ρ 1.52 (-100 ° C). Thermally stable up to 1150° C. Trifluoromethane can be stored in glass flasks or underwater.
Руководство по неорганическому синтезу. Брауэра Г. – Ч. 1 – 246. (Guide to preparative inorganic chemistry, H. Brauer, Vol. 1, 246)
Вег., 69, 299 (1936).
J. Soc. Chem. Ind., 66, 429 (1947).
CHF3, FC-23, fluorocarbon-11, fluoroform, Freon 23, trifluoromethane
Fluoroform, TRIFLUOROMETHANE, Methane, trifluoro-, Carbon trifluoride, Halocarbon 23, Fluoryl, Freon 23, Methyl trifluoride, Refrigerant 23, Propellant 23, Arcton 1, R 23 (halocarbon), Freon F-23, 75-46-7, FC 23 (fluorocarbon), Genetron-23, HFC-23, Freon R 23, R 23, HSDB 5207, XPDWGBQVDMORPB-UHFFFAOYSA-N, EINECS 200-872-4, UN1984, UN3136, BRN 1731035, Fluorym, Arcton, Carbon trifluoridm, Methyl trifluoridm, Genetron 23, Genetron HFC23, AC1L1MDU, AC1Q4KNO, CF3H, CHF3, Trifluoromethane (HFC-23), UNII-ZJ51L9A260, 295337_ALDRICH, HFC 23, CHEBI:41550, CTK2H7453, MolPort-001-777-215, FC 23, ZJ51L9A260, Trifluoromethane, refrigerated liquid, AR-1J0855, KM1695, PC7400, AKOS015853018, Trifluoromethane or Refrigerant gas R 23 [UN1984] [Nonflammable gas], InChI=1/CHF3/c2-1(3)4/h1, UN 1984, AN-23857, LS-90434, R-23, Trifluoromethane or Refrigerant gas R 23, TR-033668, FT-0626477, 4-01-00-00024 (Beilstein Handbook Reference), I14-8757, Freon 23, Arcton 1, HFC 23, R-23, FE-13, UN 1984, Trifluoromethane, refrigerated liquid [UN3136] [Nonflammable gas], Trifluoromethane, refrigerated liquid [UN3136] [Nonflammable gas], Trifluoromethane or Refrigerant gas R 23 [UN1984] [Nonflammable gas], 185009-29-4
Trifluoromethyl, CID6373, c0802, 79329-89-8, CFT