because alkoxides are a stronger base than water?
anyway, if you'd utfse, you'd have found this:
Post 257912 (https://www.thevespiary.org/talk/index.php?topic=11282.msg25791200#msg25791200)
(Antoncho: "Alkali metal alkoxides: finally, OTC!", Novel Discourse)
The post hypo referenced is very easy and very OTC.
Post 257912 (https://www.thevespiary.org/talk/index.php?topic=11282.msg25791200#msg25791200)
(Antoncho: "Alkali metal alkoxides: finally, OTC!", Novel Discourse)
NaOH + CaO + EtOH -> NaOEt + Ca(OH)2(s)
The equilibrium is very much favoring the NaOEt.
CaO is very easy to make from limestone (chalk) if someone is bored and has a crucible and a really hot flame source or a kiln.
Patent US2796443 (http://l2.espacenet.com/dips/viewer?PN=US2796443&CY=gb&LG=en&DB=EPD)
1956 to Dow Chemicals, describes a process for the production of alkali-alkoxides which requires no distillation. I basically works with an excess of hydroxide which saturates the water which can be withdrawn at the bottom, whereas the alcoholic anhydrous alcohol/alkoxide solution is withdrawn at top of a reactor.
Whuups. Alkoxide and anhydrous alcohol in one step. Nice, isnt it? :)
Rhodium: Drying EtOH with calcium carbide is an established method I thought up to now?
ADDON: Yes it is. Of course calcium alkoxide is formed, but this decomposes into alcohol and calcium hydroxide in the presence of water. Calcium hydroxide itself will NOT react with alcohol to form the alkoxide and so this is finished, the equilibrium shifts in the right direction...
Patent US1978647 (http://l2.espacenet.com/dips/viewer?PN=US1978647&CY=gb&LG=en&DB=EPD)
PS: good test Nicodem, because I was doing KOH/methanol in the meantime. voluminous, very fine precipitate, some of which goes right through doubled up real filter paper in the buchner, even with repeated passes through the filter cake. yes, the amount of acetone used is huge, there will be some drying experiments i'm sure.
PPS: i better mention the evil word "aldol". i think that is the correct thought here, but haven't looked in to it. the filter cake has to be washed with some solvent fast and well. this is not so bad on the original precipitation (not the best word, because its so fine it doesnt move down very fast) because whatever bad reaction between the base and acetone does not happen very fast. and the crystals come out instantly, as Nicodem says. you have at least 5 minutes before things darken, at least if you're using the same crappy chemicals that i am.
i used xylene, and the residue still had an acetone smell, and started to darken. its hot and humid here today, maybe the cake absorbed water in the short time that it was exposed, and this caused problems with the xylene wash.
Damn, I searched the net and there are tens of pages mentioning the H2O:EtOH:toluene azeotrope and none talks about its composition. Anyway, its b.p. is 74.6°C.
(see http://separationprocesses.com/Distillation/DT_Chp06c06.htm (http://separationprocesses.com/Distillation/DT_Chp06c06.htm)
<=worth reading!)
I know this is off topic, but I remember there was a discussion on how to azeotropicaly dry the acetic acid. Here is a method: http://separationprocesses.com/Distillation/DT_Chp06c07.htm (http://separationprocesses.com/Distillation/DT_Chp06c07.htm)
EDIT
Gsus and Organikum, the patents you two found are excellent. I performed a preliminary test.
I first checked if concentrated aqueous NaOH is mishelable with ethanol. It is not. This means that the patent Organikum found is not bullshit but quite probably works! :)
Then I prepared an saturated ethanolic NaOH solution by heating a few grams of NaOH pellets in 15ml of commercial ethanol (96% ?). When cooled I decanted the liquid assuming that most of the water would remain on NaOH pellets like claimed in the Patent US2796443 (http://l2.espacenet.com/dips/viewer?PN=US2796443&CY=gb&LG=en&DB=EPD)
. I then treated the ~12ml of clear solution with 10ml of (not dried) acetone and a white crystalline precipitate immediately formed just as described in Patent US1978647 (http://l2.espacenet.com/dips/viewer?PN=US1978647&CY=gb&LG=en&DB=EPD)
. 10ml more of acetone was added and more precipitate formed.
It seems that quite a lot of acetone is needed for this method as it still forms more precipitate if some more acetone is added. But the patent claims that it can bee done all in one step before even preparing the ethanolic solution, therefore by simply mixing NaOH, EtOH and acetone. This should require less EtOH (as NaOH is only soluble up to ~12% in EtOH), but it should not give a pure product.
Anyway, the precipitate covered the bottom up to 5ml out of the 35ml total so it should not bee such a bad yield, though it looks somewhat fluffy and light. It looks quite crystalline like as opposed to NaOH, so it should bee NaOEt. I would have never thought that it is so easy. And NaOEt is such a precious and useful reagent. ;)
My attempts to prepare some NaOEt as described by Nicodem in Post 512006 (https://www.thevespiary.org/talk/index.php?topic=10688.msg51200600#msg51200600)
(Nicodem: "The patents work", Newbee Forum) failed, but I can't figure out why. Here is an outline of the procedure:
20 pellets of NaOH in 50 mL of EtOH were refluxed for about 2 hours. The mixture was allowed to cool to room temperature and ~20 mL of the solution was decanted into another flask. To this was then added 20 mL of acetone (not dried) and immediately some white, fluffy precipitate formed, but it disolved when the flask was shaken. Then the rest of the acetone was added, precipitate formed, but again it disolved upon shaking the flask. Unfortunately I ran out of acetone so I couldn't add any more.
So, what went wrong? My guess is that the amount of acetone added was to small to precipitate NaOEt, but I would like to hear some thoughts from more experienced bees.