Ive been mucking around with some Bromo-chloro-dimethylhydantoin (BCDMH) and metabisulfite ala Lens writeup so as to source some bromine/ide to go on and try some methyl bromide preps.No worries works as written. Then it occured to me that maybe I could skip having to isolate any bromine or bromide and use the same reagents to hopefully produce the methyl bromide in methanol.
Thinking along the lines that yeah the bisulfite will liberate bromine from BCDMH, but shouldnt a 2 fold excess also reduce the bromine to HBr and Sulfuric/sulfurous acid which should then form the alky bromide in situ???
So without any decent set of scales and using ethanol instead of methanol I gave it slap-dash whirl. Chilled all the well ground reactants, @1:2.5 BCDMH to NaHSO3 and healthy splash of ethanol(methylated spirits) to minus zero and threw em all together in a test tube. Initially the solids turned orange as if to indicate bromine but after about a minute as the tube was allowed to warm a touch, the bromine colour completely faded and a mildly exothermic reaction kicked with vigorous gas evolution(HBr I might stupidly assume). The reaction subsided and a slightly ethereal/alcoholic smell was noted permeating from the tube.No halogen odour was noted.(yes I realise you shouldnt go huffing unkown compounds from test-tubes)
Anyway I was left with a slightly cloudy white sollution with a white precipitate( likely simply an excess of either reagent).
After one hour sitting at room temperature the sollution has cleared and turned slightly yellow.I havent let my finely tuned analytical nostrils loose yet again.
My questions are,
1) Does this make any sense to anyone?
2) Does the theory back my hypothesis? If so is the stoichiometry close to being correct?
3) Is there any quick and easy way you can suggest I determine if methyl bromide is formed.
4) Any better conditions to try it under?
5) If Im not completely off base and there is a chance of what Im saying does have some merit, would someone a bit better equipped be prepared to give it a propper shot.
Thinking along the lines that yeah the bisulfite will liberate bromine from BCDMH, but shouldnt a 2 fold excess also reduce the bromine to HBr and Sulfuric/sulfurous acid which should then form the alky bromide in situ???
So without any decent set of scales and using ethanol instead of methanol I gave it slap-dash whirl. Chilled all the well ground reactants, @1:2.5 BCDMH to NaHSO3 and healthy splash of ethanol(methylated spirits) to minus zero and threw em all together in a test tube. Initially the solids turned orange as if to indicate bromine but after about a minute as the tube was allowed to warm a touch, the bromine colour completely faded and a mildly exothermic reaction kicked with vigorous gas evolution(HBr I might stupidly assume). The reaction subsided and a slightly ethereal/alcoholic smell was noted permeating from the tube.No halogen odour was noted.(yes I realise you shouldnt go huffing unkown compounds from test-tubes)
Anyway I was left with a slightly cloudy white sollution with a white precipitate( likely simply an excess of either reagent).
After one hour sitting at room temperature the sollution has cleared and turned slightly yellow.I havent let my finely tuned analytical nostrils loose yet again.
My questions are,
1) Does this make any sense to anyone?
2) Does the theory back my hypothesis? If so is the stoichiometry close to being correct?
3) Is there any quick and easy way you can suggest I determine if methyl bromide is formed.
4) Any better conditions to try it under?
5) If Im not completely off base and there is a chance of what Im saying does have some merit, would someone a bit better equipped be prepared to give it a propper shot.
METHYLBROMIDE.pdf