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Dibromomethane is used as solvent in organic synthesis. It acts as an intermediate in the manufacture of specialty chemicals, agrochemicals and pharmaceuticals. It is useful as extractant and utilized for the determination of 5-nitroimidazoles (5-NDZ) in environmental waters. It is involved in the convertion of catechols to their methylenedioxy derivatives.
For in situ formation of dibromomethyllithium by reaction with lithiated 2,2,6,6-Tetramethylpiperidine, A18712, and use in a one-pot ester homologation sequence, safer and more convenient than the classical Arndt-Eistert (diazomethane) method, see: Org. Synth. Coll., 9, 426 (1998):
Reaction with NaHMDS generates monobromocarbene, which reacts with alkenes to give bromocyclopropanes: Synthesis, 201 (1972). It can also be generated by reaction with diethylzinc in the presence of O2: J. Chem. Soc., Chem. Commun., 364 (1975).
The Simmons-Smith reaction (see Diiodomethane, A15457) may be extended to the use of dibromomethane in the cyclopropanation of simple electron-deficient alkenes, using a reducing agent prepared from NiBr2, NaI and Zn: Bull. Chem. Soc. Jpn., 56, 1025 (1983); or with CuCl/Zn: J. Org. Chem., 55, 2491 (1990).
With TiCl4/Zn, methylenation of ketones occurs, as a useful mild alternative to the Wittig reaction: Tetrahedron Lett., 23, 4293 (1982); Org. Synth. Coll., 8, 386 (1993). For a variant using Zn, CuCl and catalytic TiCl4, see: J. Org. Chem., 54, 2388 (1989).
With alcohols, formaldehyde acetals can be formed under phase-transfer conditions: Bull. Chem. Soc. Jpn., 66, 2149 (1993). Diols give methylenedioxy derivatives, which are components of many biologically-important molecules. For use of KF in DMF as base in the methylenation of catechols, see: Tetrahedron Lett., 3361 (1976). KOH in DMSO has been recommended for the methylenation of base-stable carbohydrate diols: Synthesis, 421 (1982). For the methylenation of ribonucleosides under phase-transfer conditions, see: Synthesis, 715 (1981).
Chorazewski, M.; Troncoso, J.; Jacquemin, J. Thermodynamic Properties of Dichloromethane, Bromochloromethane, and Dibromomethane under Elevated Pressure: Experimental Results and SAFT-VR Mie Predictions. Ind. Eng. Chem. Res. 2015, 54 (2), 720-730.
Stoeckel, D.; Wallacher, D.; Zickler, G. A.; Thommes, M.; Smarsly, B. M. Elucidating the Sorption Mechanism of Dibromomethane in Disordered Mesoporous Silica Adsorbents. Langmuir 2015, 31 (23), 6332-6342.
Dichiarazioni di rischio (UE): H332
Harmful if inhaled.
Dichiarazioni precauzionali: P261-P271-P304+P340-P312a
Avoid breathing dust/fume/gas/mist/vapours/spray. Use only outdoors or in a well-ventilated area. IF INHALED: Remove to fresh air and keep at rest in a position comfortable for breathing. Call a POISON CENTER/doctor if you feel unwell.