09-13-01 11:01
No 213142
Since acetamide is needed in Hoffmann synthesis of methylamine, I decided to collect all possible syntheses.
I. Acetamide from Acetyl chloride
In test tube put 2 mL of conc. NH3 solution and put it into ice-water bath. Drop by drop add 1 mL acetyl chloride. Add acetyl chloride slowly, so the white fumes that appear don't escape from the test tube. If precipitate does not form add some ether or ether/methanol mixture.
II. Acetamide from Acetanhydride
Put 2 mL of conc. NH3 solution into test tube and put it in ice-water bath. Drop by drop add 1 mL of Acetanhydride. In this case white fumes don't appear. To this mixture add ether/methanol mixture until precipitate forms.
III. Acetamide from Ethyl acetate
Put 2 mL of conc. NH3 solution and 1 mL Ethyl acetate into test tube and shake it. When you can see only one layer add ether or ether/methanol mixture until precipitate forms.
First 2 synthesis I performed by myself. The third one was taken from all kind of sources and improved.
Give me some chemicals and I'll give you pleasure
(Chief Bee)
09-13-01 11:42
No 213158
And the yields from the various methods? For the first two, I suspect there are hydrolysis losses from reaction of the acetylation agents with water.
(Hive Bee)
09-13-01 11:56
No 213165
Bubbling NH3 in the reagent should not provoke losses by hydrolisis, but maybe quite dangerous, doesn't it?
(Chief Bee)
09-13-01 12:00
No 213170
Not with a suck-back trap for the NH3 gas, and dilution of the acetylation reagent in an inert solvent.
(Stoni's sexual toy)
09-14-01 03:02
No 213452
Ammonium acetate and heat. Why making it more complicated and expensive than it really is.
(Newbee)
09-14-01 10:01
No 213542
This is good info, Swim has a question say you already have plenty of acetamide and would like to rearange it to MeAm gas and their must be a better way than what strike describes in TSII. I am interested in in pratice technique not theroy. Swim uses the decompisition of hexamine mostly because it is so easy.
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Hum did you get that?