Bromomethanes

Bromine is used in the manufacture of many important organic compounds including 1,2-dibromoethane (ethylene dibromide), added to petrol to prevent lead deposition which occurs by decomposition of the anti-knock —lead tetraethyl bromomethane (methyl bromide), a fumigating agent, and several compounds used to reduce flammability of polyester plastics and epoxide resins. Silver(I) bromide is used extensively in the photographic industry... 

The reaction itself works by the action of Na or K from NaOH or KOH which form what is called a catechoxide dianion with the two OHs of the catechol species. This makes the two ripe for an attack by a methylene halide which can be either DCM (methylene chloride, or dichloromethane), DBM (methylene bromide, or di-bromomethane) or DIM (methylene iodide, or diiodomethane). DCM is cheap and works pretty well, but DBM and DIM work better yet are more expensive. 

The carbon atom m bromomethane can accept an electron pair if its covalent bond with bromine breaks with both electrons m that bond becoming an unshared pair of bromide ion Thus bromomethane acts as a Lewis acid m this reaction... 

Dimethylsulfoxide Acyl and aryl halides, boron compounds, bromomethane, nitrogen dioxide, magnesium perchlorate, periodic acid, silver difluoride, sodium hydride, sulfur trioxide... 

Other Bromomethanes. Bromochloromethane [74-97-5] (methylene chlorobromide), CH2BrCl, is a clear, colorless Hquid with a characteristic sweet odor and very low freezing point, —88.0°C. Its properties include bp, 68.1°C 1.9229 g/mL 1.4808 heat of vaporization at bp, 232 J /g... 

CH3BR BROMOMETHANE -55.241 8.0199E-02 1.1207E-05 -28.16 69 C2H402 METHYL-FORMATE -350.914 1.7474E-01 1.6322E-05 -297.19... 

Chemical Designations - Synonyms Bromomethane Embafiime M-B-C Fumigant ... 

Rate constants have been measured for the reactions of boron compounds with a series of bromomethanes and bromofluoromethanes. Previously it was shown that the reactivity of the chlorine in chlorofluoromethane is substantially reduced by increasing fluorine substitution. The corresponding decrease in the reactivity of bromolluoromethane u as not observed [ifS]. 

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