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Author: Subject: The short questions thread (3)
solo
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[*] posted on 8-8-2012 at 19:50


....the hydrolysis of phenylacetamide will produce PAA, and a by product of an amine.... will the amine be methylamine?or ammonium chloride if hydrolysed with HCL or ammonium sulfate if hydrolysed with sulfuric acid? .. once the phenylacetamide has been put into solution in methanol and a strong solution of an acid or a base is added and refluxed for three hours...... does anyone have first hand notes on the hydrolysis, ....bits and pices of the info was gathered at organic synthesis and reading Marchs 6th edition .....solo

[Edited on 9-8-2012 by solo]




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[*] posted on 11-8-2012 at 19:06


Quote: Originally posted by DJF90  
I've personally rotavapped some formalin to the point that it becomes much more viscous and begins to cloud. It's poured out on a hard surface in a thin layer (read: pyrex baking dish) and as it cools it solidifies. Scraping this solid into flakes or "shavings" will allow proper desiccation over anhydrous calcium chloride. The solid is removed and ground in a pestle and mortar before being returned to the desicator. The fine, dry powder that is obtained is paraformaldehyde, (CH2O)n.


Interesting, so do you mean to say that the CH2O would "rather" polymerize than evaporate?
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[*] posted on 13-8-2012 at 09:37


Will the Bucherer reaction displace a hydroxy by an amino group in an alkyl.....?..or only on a benzene ring?..solo



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[*] posted on 13-8-2012 at 10:24


Quote: Originally posted by solo  
Will the Bucherer reaction displace a hydroxy by an amino group in an alkyl.....?..or only on a benzene ring?..solo

The mechanism is depicted on the Wikipedia entry for Bucherer reaction. You can now answer your own question.
Also, the scope of this reaction does not expand to just any phenol. It has to be a phenolic compound that has a substantial equilibrium for the reverse enolization.
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[*] posted on 14-8-2012 at 08:35


Nicodem.....thanks for the reply, I had read,

"Replacement of hydroxy by amino groups occurs in the Bucherer reaction; the reagent is an aqueous solution of bisulfite and ammonia or an amine, and the hydroxy groups of naphthols or resorcinol are most easily replaced. The Bucherer reaction occurs via the keto tautomers of the phenols (163), and is not to be classed as aromatic substitution.
The 4-hydroxy group in 2,4-dihydroxyquinoline may be replaced by amines; hydrochloric acid aids the reaction with aniline (138). Aminolysis of an o-nitro- phenol has been reported, but the reaction is more difficult than that of the corresponding nitrophenyl alkyl ethers (540). Here again it might be argued that these direct replacements of hydroxy groups are in reality condensations of the keto tautomers of the phenols."

......source,

Aromatic Nucleophilic Substitution Reactions- Bunnett and Zahler

http://filecloud.io/nd8lh7eo

Ref.163-DRAKEO: Organic Reactions, Vol. I, p. 105. John Wiley and Sons, Inc., New York (1942).....this is located in the SM library

.....but i guess wanted for it to work on an alkyl chain....hence, my stubborn question...which is now answered ....thanks....solo



[Edited on 14-8-2012 by solo]




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[*] posted on 1-9-2012 at 14:13


The preparation of tetramine copper (II) sulfate is usually carried out with concentrated ammonia solution.

Can it be done by using household ammonia, with the quantities adjusted accordingly?




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[*] posted on 1-9-2012 at 14:33


Quote: Originally posted by Hexavalent  
The preparation of tetramine copper (II) sulfate is usually carried out with concentrated ammonia solution.

Can it be done by using household ammonia, with the quantities adjusted accordingly?


Yes but if you want crystals of the tetramine copper II sulphate of it You will find 28% ammonia more suitable.




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[*] posted on 2-9-2012 at 04:36


Why? Is it just because there will be less water present with the concentrated ammonia? My plan was just to add enough ammonia solution to aqueous copper sulfate to form copper hydroxide and then to complex the precipitate again, before adding ethanol to precipitate out the tetramine copper sulfate.



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[*] posted on 9-9-2012 at 03:33


Can N-ethylhydroxylamine react with methyllithium to produce ethylmethylamine. if it works, then ethyllithium could be used for diethylamine(ethylethylamine) and propyllithuim could be used for ethylpropylamine. Will it work?



0 Ethylmethylamine.png - 7kB


[Edited on 9-9-2012 by ChemistryGhost]




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[*] posted on 9-9-2012 at 05:43


Would liquid sulphur, heated a bit above its melting point (~115 °C), attack food grade silicone polymer? Would vulcanization occur and affect it? I have an idea, but I'm not willing to do any experiments yet.



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[*] posted on 10-9-2012 at 19:45


A couple of years ago I tried some hydroforming with my pressure washer but it didn't have enough pressure. It says 1800 PSI on it, but it's old so I'm sure it's less than that. Anyone know of a cheap and readily available pump (automotive maybe?) that can get to pressures of say 2500 PSI and higher? If I can find the right pump I'd like to give this another try. I'm trying to form 4" diameter 1.6mm thick copper circles into a conical cavity. Considering how incredibly soft copper is in it's annealed state, I thought my pressure washer would be plenty adequate. I thought wrong :P
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[*] posted on 11-9-2012 at 05:32


Quote: Originally posted by Endimion17  
Would liquid sulphur, heated a bit above its melting point (~115 °C), attack food grade silicone polymer? Would vulcanization occur and affect it? I have an idea, but I'm not willing to do any experiments yet.
The experiment to do is to immerse some samples of the silicone you want to use in liquid sulfur and pull them out an periodic intervals. Wash in toluene to clean them. Examine, with a magnifier if needed.

I would imagine that you'll get an attack. What I don't know is the degradation rate. I've not done the experiment, but I imagine you'll get liberation of H2S and dehydrogenation of the polymer.
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[*] posted on 11-9-2012 at 05:58


Quote: Originally posted by watson.fawkes  
Quote: Originally posted by Endimion17  
Would liquid sulphur, heated a bit above its melting point (~115 °C), attack food grade silicone polymer? Would vulcanization occur and affect it? I have an idea, but I'm not willing to do any experiments yet.
The experiment to do is to immerse some samples of the silicone you want to use in liquid sulfur and pull them out an periodic intervals. Wash in toluene to clean them. Examine, with a magnifier if needed.

I would imagine that you'll get an attack. What I don't know is the degradation rate. I've not done the experiment, but I imagine you'll get liberation of H2S and dehydrogenation of the polymer.


Thanks. I've got only one piece of it and I don't want to spend money on this experiment. Plus I don't have the opportunity to do it soon...




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[*] posted on 11-9-2012 at 15:48


Can 4A molecular sieves be used to remove water vapor from H2 gas? Sigma says 3A is suited to this purpose but I only have 4A. Do molecular sieves even absorb enough water to make them viable for drying H2 mixed with steam or would I just be better off passing the hydrogen over sodium sulfate or a similar chemical dessicant?



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[*] posted on 11-9-2012 at 17:45


Quote: Originally posted by gnitseretni  
A couple of years ago I tried some hydroforming with my pressure washer but it didn't have enough pressure. It says 1800 PSI on it, but it's old so I'm sure it's less than that. Anyone know of a cheap and readily available pump (automotive maybe?) that can get to pressures of say 2500 PSI and higher? If I can find the right pump I'd like to give this another try. I'm trying to form 4" diameter 1.6mm thick copper circles into a conical cavity. Considering how incredibly soft copper is in it's annealed state, I thought my pressure washer would be plenty adequate. I thought wrong :P


Seems like you'd need a hydraulic pump of some sort, and they don't really come cheap. Even a hand-operated pump (which would be OK for your purpose since you don't need any significant flow) sells for over $100.




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[*] posted on 11-9-2012 at 18:03


Ha, I just bought a hand operated pump for $70 five mins ago. Goes up to 9700 PSI. Should be enough ;)
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[*] posted on 16-9-2012 at 10:11


I can't find any answer and hope it's new.

Can the ice build up from a freezer be classed as "UNCONVENTIONAL" distilled water when melted? mm
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[*] posted on 16-9-2012 at 10:22


Quote: Originally posted by gnitseretni  
A couple of years ago I tried some hydroforming with my pressure washer but it didn't have enough pressure. It says 1800 PSI on it, but it's old so I'm sure it's less than that. Anyone know of a cheap and readily available pump (automotive maybe?) that can get to pressures of say 2500 PSI and higher? If I can find the right pump I'd like to give this another try. I'm trying to form 4" diameter 1.6mm thick copper circles into a conical cavity. Considering how incredibly soft copper is in it's annealed state, I thought my pressure washer would be plenty adequate. I thought wrong :P


You can get vac pressure flow connections for air compressors, there may be one for water aplications. Add a water cooling system to aid in getting higher pressure's. maybe the pressure washer you already have can get you there. just a thaught. MM
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[*] posted on 25-9-2012 at 06:52


Quote: Originally posted by crazyboy  
Can 4A molecular sieves be used to remove water vapor from H2 gas? Sigma says 3A is suited to this purpose but I only have 4A. Do molecular sieves even absorb enough water to make them viable for drying H2 mixed with steam or would I just be better off passing the hydrogen over sodium sulfate or a similar chemical dessicant?


4A MS will absorb water, if they are well activated (usually bought that way, but if old, they can be heated under vacuum to dry them.) You could also use a chemical desicant like NaSO4, although it is slow to absorb, but it will be OK if there is a lot of H2O. But these types of drying agents can only do so much, so fast, so the H2 needs to be relatively dry when it starts to have them dry it well. If you have very wet H2, it may take several drying steps/towers to dry it well. But even H2 generated from water hydrolysis can be dried sufficiently with a drying column or two, under most cases. We have used hydrolysis H2 generators for H2 in the lab, and they worked fine.
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[*] posted on 25-9-2012 at 07:20


Quote: Originally posted by Dr.Bob  
But even H2 generated from water hydrolysis can be dried sufficiently with a drying column or two
A bubbler through concentrated sulfuric acid seems to be the standard first element in any drying train for gases generated from aqueous solutions. It will eventually dilute, of course, and lose its drying power.

Also, the reference I have on hydrogen brazing recommends 5A sieves for taking water vapor from tank hydrogen. My guess is that the adsorption rate may be a bit higher that with 4A.
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[*] posted on 2-10-2012 at 05:06
making sodium fluoride


can calcium fluoride be converted to sodium fluoride by boiling with soda, akin to the method starting with barium sulfate?

http://www.sciencemadness.org/talk/viewthread.php?tid=9123

CaF2 is even more soluble than BaSO4..
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[*] posted on 6-10-2012 at 00:17


Quote: Originally posted by solo  
....the hydrolysis of phenylacetamide will produce PAA, and a by product of an amine.... will the amine be methylamine?or ammonium chloride if hydrolysed with HCL or ammonium sulfate if hydrolysed with sulfuric acid? .. once the phenylacetamide has been put into solution in methanol and a strong solution of an acid or a base is added and refluxed for three hours...... does anyone have first hand notes on the hydrolysis, ....bits and pices of the info was gathered at organic synthesis and reading Marchs 6th edition .....solo

[Edited on 9-8-2012 by solo]


Vogel 3rd ed uses 30% caustic refluxed for 30 mins, reaction followed via NH3 coming off (ie past the condenser), when this ceases then finished. Also same edition uses refluxing HCl, reaction completed when solution loses turbidity.
if you have time i suggest just leaving it in 30%hcl for a week.




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[*] posted on 15-10-2012 at 12:23


If I prepare methyl benzoate with methanol and benzoic acid I will get that great fruity smell that we all know and love, but, if I prepare benzyl methanoate, i.e. with benzyl alcohol and methanoic acid (formic acid), will it still have the same smell?



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[*] posted on 15-10-2012 at 12:26


Quote: Originally posted by Hexavalent  
If I prepare methyl benzoate with methanol and benzoic acid I will get that great fruity smell that we all know and love, but, if I prepare benzyl methanoate, i.e. with benzyl alcohol and methanoic acid (formic acid), will it still have the same smell?


Why would it...the molecule is a different shape.




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[*] posted on 15-10-2012 at 12:41


That was what I thought...although I wasn't sure as the aromatic ring and aliphatic substituent were in the same 'place'.



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