-4— 
BOULIN, C, and SUION, L. J. (7) 
Preparation of methyl chloride and methyl bromide from dimethyl 
sulfate. [Paris] Acad, des Sci. Compt, Rend. 170: 595-597. 
1920. [In French,] 
In the presence of hydrochloric acid, water hydrolyzcs dimethyl 
sulfate to give, in part, methyl sulfuric acid and methyl chloride. 
With 3 parts of hydrochloric acid (22° Be'.) and 1 part of water 90 
percent or more of practically pure methyl chloride results. A 
saturated solution of sodium chloride works nearly as well, but the 
solution should be warmed to 60°-65° C. to start the reaction. Hy- 
drobromic acid gives a similar reaction, but aqueous sodium bromide, 
slightly acidified with sulfuric acid, is preferred, giving (at 30°- 
35° C.) methyl bromide in 90 percent yield. Methyl bromide is very 
soluble in glacial acetic acid (42 gm. per 100 gm, of acetic acid 
at 24° C.). These methods are recommended for laboratory prepara- 
tions, 
BUSBEY, R. L., and DRAKE*, N. L. (8) 
Determination of small quantities of methyl bromide in air. Indus. 
and Sngin. Chcm. , Analyt. Ed. 10: 390-392. 1938. 
The method proposed is for determining the methyl bromide con- 
tent of fumigated air. The sample of air is subjected to the sapon- 
ifying effect of potassium hydroxide in alcohol, for which purpose 
a special apparatus has been devised. The alcohol is finally re- 
moved by distillation, the bromide oxidized to bromatc hy sodium 
hypochlorite, and the bromatc determined iodomctrically, 
BYGDEN, A. (9) 
Preparation of methyl bromide. Jour, f . Prakt. Chcm. 83: 421-424. 
1911, [in German,] 
Methyl bromide is obtained in 83-84 percent yield (as against 
44,5 percent by the bromine and phosphorus method) by adding 450 
gm. of methyl alcohol to GOO gm. of sulfuric acid, adding gradually 
230 gm. of water and 300 gm. of powdered potassium bromide to the 
cold mixture, and heating until gas ceases to be evolved. 
(10) 
Preparation of methyl bromide. Jour. f. Prakt. Chcm. 104: 285- 
288. 1922. [in Gorman.] 
Sulfuric acid (95 percent) is first diluted with water, the 
methyl alcohol is slowly added with cooling, followed by pulver- 
ized potassium bromide, and the flask with reflux condenser is 
slightly warmed. The evolved gases arc passed through water or 
sodium hydroxide to remove hydrobromic acid and then through two 
bottles of concentrated sulfuric acid. Methyl bromide is then con- 
densed in an ioc-sali bath. The yield varied between 93,5 and 97.3 
percent, depending on the proportion of methyl alcohol to the other 
reactants. 
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