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stygian
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[*] posted on 11-5-2010 at 18:31


Can nitroalkenes (b-nitro alcohols) undergo a retro-aldol type reaction? Or shall I say, what conditions would be needed to coerce this into happening?
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[*] posted on 12-5-2010 at 05:17


Quote: Originally posted by 12AX7  
If you dissolve only a small amount, the CO2 may remain in solution. Can you get a pile of the stuff and drop acid on it (>10% HCl would be best)?

Tim


I will try making more but right now i don't even have 1 gram.

then i will use 20 B degree HCL to try.
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[*] posted on 13-5-2010 at 04:16


Can Phenylpropanolamine be produced by the reductive amination of L-Pac Via the below method except the catalyst (raney nickel) is substituted for Al/Hg?

Run down for people to lazy to open the link,



Quote:

Compound 1 5g [α]D25 -155° (containing 4.28 g pure (R)-(–)-1-hydroxy-1-phenyl-2-propanone, 0.03 mol·dm-3) was taken up in 15 mL of benzene. 11.4 mL (0.17 mol·dm-3) of 25% ammonia and 0.5 g Raney nickel were added and hydrogen was passed for 2.30 h at 50 psi. After completion of the reaction, the reaction mixture was filtered off. concentrated hydrochloric acid (7 mL) was added to adjust the pH to 5.5. The solution was concentrated under reduced pressure. The viscous mass was dissolved in absolute ethanol and dry ether was added to the solution. A colourless compound crystallised from absolute ethanol, mp 192–194°C (literature cited 190-194°C, [α]D25 0°, was obtained. Yield: 30%, 1.61 g.


http://www.erowid.org/archive/rhodium/chemistry/ppa.l-pac.ra...

Thanks for any help given.
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[*] posted on 15-5-2010 at 15:44


Yes, but yields will likewise be low.
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manimal
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[*] posted on 15-5-2010 at 15:49


I have in mind a reaction that alkylates an m-nitrobenzyl-alkyl-ketone at the alpha-carbon with an alkyl chloride in a biphasic PTC environment. Is anyone cognizant of references that affect this or any analogous reactions?

[Edited on 15-5-2010 by manimal]
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[*] posted on 15-5-2010 at 16:58


Quote: Originally posted by Pope  
Can Phenylpropanolamine be produced by the reductive amination of L-Pac Via the below method except the catalyst (raney nickel) is substituted for Al/Hg?
L-Pac? Is that some of that drug cook's terminology that isn't appropriate on a chemistry forum?
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[*] posted on 15-5-2010 at 19:21


Quote: Originally posted by entropy51  
L-Pac? Is that some of that drug cook's terminology that isn't appropriate on a chemistry forum?


I don't think so. It stands for l-phenylacetylcarbinol, which is legit nomenclature.
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[*] posted on 18-5-2010 at 04:33


Quote: Originally posted by manimal  
I have in mind a reaction that alkylates an m-nitrobenzyl-alkyl-ketone at the alpha-carbon with an alkyl chloride in a biphasic PTC environment. Is anyone cognizant of references that affect this or any analogous reactions?

A cursory SF search gives these related examples:

Bioorganic & Medicinal Chemistry, 2009, 17, 2963-2974 describes an alpha-C-alkylation of m-nitrobenzyl p-methoxyphenyl ketone with methyl bromoacetate (NaH/DMF);

WO2005070420 describes alpha-C-methylation of 4-fluoro-3-nitrobenzyl cyclohexyl ketone with methyl iodide (NaH/THF, 2h, rt);

Chemical & Pharmaceutical Bulletin, 1969, 17, 605-610 describes alpha-C-propargylation of 3-chloro-5-nitrobenzyl methyl ketone with propargyl bromide (NaOEt/EtOH);

These are only examples on substrates containing the 3-nitrobenzyl moiety. Otherwise, there are plenty of examples on other benzyl alkyl/aryl ketones. Some use KOtBu or NaH, others use NaOH under PTC conditions (quats or crown ethers; see Tetrahedron Letters, 1971, 1351-1352 for a method). If the electrophile is a fairly reactive primary alkyl bromide or iodide, the reaction should give reasonably good yields. With alkyl chlorides under PTC conditions, I doubt you would get anything useful, unless of course it is a benzyl or allyl chloride. Rather use an alkyl bromide/iodide/tosylate/etc. Likewise secondary alkyl halides are unlikely to work, and if they do the yields will suffer greatly.

Edit: In case you want to alkylate with beta-chloroethylamines in a biphasic system, consider that here the actual alkylating species (aziridinium ions) are cations and thus partition into the aqueous phase (and succumb to hydrolysis) rather than stay in the organic phase to react with the substrate. (just guessing about the nature of the electrophile you intent to use)

[Edited on 18/5/2010 by Nicodem]




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[*] posted on 20-5-2010 at 16:41


Nevermind, found the answer..

[Edited on 21-5-2010 by 497]
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[*] posted on 20-5-2010 at 19:37


If possible could someone link me to a viable source, I've only found one place where they said you could substitute it for Al/Hg but there was no hard facts.
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[*] posted on 25-5-2010 at 04:21


Is there an similar property for fluid flow in pipes cf/ starting friction and sliding friction for solid surfaces moving against one another?



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[*] posted on 25-5-2010 at 06:38


Quote: Originally posted by Panache  
Is there an similar property for fluid flow in pipes cf/ starting friction and sliding friction for solid surfaces moving against one another?
For ordinary Newtonian fluids, no. The equivalent terms would be "standing viscosity" and "moving viscosity", but there's only a single viscosity. The Newtonian fluid model, though, doesn't nearly model all real fluids. One non-Newtonian model uses shear-dependent viscosity, which models thixotropic and shear-thinning materials.
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[*] posted on 25-5-2010 at 07:44


Quote: Originally posted by watson.fawkes  
Quote: Originally posted by Panache  
Is there an similar property for fluid flow in pipes cf/ starting friction and sliding friction for solid surfaces moving against one another?
For ordinary Newtonian fluids, no. The equivalent terms would be "standing viscosity" and "moving viscosity", but there's only a single viscosity. The Newtonian fluid model, though, doesn't nearly model all real fluids. One non-Newtonian model uses shear-dependent viscosity, which models thixotropic and shear-thinning materials.


apologies then i guess this gets far more complex quickly however i'll ask anyway. The circumstance i'm interested in is a recirculating pump on startup running nothing other than water or water glycol. Does the pump initially do more work until the circuit is flowing or does the work being done by the pump simply gradient upwards leveling out once the pressure in the system is obtained. Are equations available to predict the pressure gradient in the system from startup until i guess you could call it steadystate.




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[*] posted on 25-5-2010 at 11:45


.....have been pondering on the Cleisen Rearrangement of c6h5-ch2-ch2-(0-ch3) , following the rearrangement it would make phenylacetone.......it's a question not a fact and what would the ether be called?......also can the rearrangement function as outline or does it only with an allyl group.......solo



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[*] posted on 25-5-2010 at 12:44


(2-methoxyethyl)benzene I know of no common names off the top of my head sorry but that may help you in finding the slang for it.




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[*] posted on 25-5-2010 at 13:09


Quote: Originally posted by solo  
.....have been pondering on the Cleisen Rearrangement of c6h5-ch2-ch2-(0-ch3) , following the rearrangement it would make phenylacetone.......it's a question not a fact and what would the ether be called?......also can the rearrangement function as outline or does it only with an allyl group.......solo


I think you mean Claisen rearrangement. You need an allyl vinyl ether, which you do not have. Part of the aromatic ring can stand in for one of the double bonds, but you don't have that set up properly either.




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[*] posted on 25-5-2010 at 17:03


Quote: Originally posted by Panache  
The circumstance i'm interested in is a recirculating pump on startup running nothing other than water or water glycol. Does the pump initially do more work until the circuit is flowing or does the work being done by the pump simply gradient upwards leveling out once the pressure in the system is obtained. Are equations available to predict the pressure gradient in the system from startup until i guess you could call it steadystate.
Both the fluids you mention are perfectly good Newtonian fluids, at least to an approximation better than you could (easily) measure at home. So to your first question, there's no extra work at startup due to viscosity effects.

Non-steady-state pressure gradients transmit at the speed of sound in the fluid, which is quite fast, about 1.5 km/s. The sonic transmission time across the diameter of your lab-scale apparatus is only a millisecond at most, which is nothing to worry about.
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[*] posted on 26-5-2010 at 08:17


I've been googling all morning but can't seem to get anywhere with this: does anybody know of a non-electrolytic method of copper methoxide production?



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[*] posted on 29-5-2010 at 17:38


Some text in patent 5006508 says:

'...A typical reaction may be that between lithium metal and anhydrous methanol to produce a methanolic solution of lithium methoxide. This lithium methoxide solution is filtered to remove any precipitate that may have formed and the filtered solution is added to a solution of anhydrous cupric chloride in anhydrous methanol. The lithium methoxide and cupric chloride react to form copper (II) methoxide which precipitates and lithium chloride which is soluble in methanol. The copper methoxide is collected by filtration and washed with several methanol washes...'

There is also this, of which I can however only see the abstract:
Kendric J. Nelson, Ilia A. Guzei, Gregory S. Lund, Robert W. McGaff, Copper(II) methoxide: direct solventothermal synthesis and X-ray crystal structure, Polyhedron, Volume 21, Issue 20, 1 September 2002, Pages 2017-2020, ISSN 0277-5387, DOI: 10.1016/S0277-5387(02)01132-4.
(http://www.sciencedirect.com/science/article/B6TH8-46MK5SK-2...)
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[*] posted on 1-6-2010 at 04:54


Hmmm... I continued researching into it more and I don't know how it evaded me, but I would like to verify if that L-Pac is reduced to either Phenylpropanolamin or Ephedrine by the same way P2P is reduced to Amphetamine or Methamphetamine e.g. reductive alkylation/amintion. If so I feel like quite the moron and would like to apologise for the inconvenience.

This is not drug related but it was the only way to lay mention of the reduction processors.
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[*] posted on 5-6-2010 at 17:54


Pope you need to understand the mechanics of why it would form Ephedrine or PPA. Look into why normal Al/Hg reductive amination work and the mechanics behind it. PS: you will more then likely not find the mechanics information on Rhodiums archives. Look more for the reductive amination of ketones instead of limiting yourself to a certine substate in general. Also look into imine as well on wiki to get an idea of whats truely getting reduced.


==========================================
QUESTION:


Does anyone have the solublity data of the Vanillin Bisulfate adduct it either H2O or EtOH?

Im attempting to extract it from an impure OTC Vanilla extract which contains mostly H2O and some EtOH so I figured add sodium Metabisulfate till saturation and quickly filter then add EtOH to precipitate the adduct but I want to make sure I got what I desire.

[Edited on 6-6-2010 by Sedit]





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[*] posted on 5-6-2010 at 18:27



QUESTION:


Does anyone have the solublity data of the Vanillin Bisulfate adduct it either H2O or EtOH?

Im attempting to extract it from an impure OTC Vanilla extract which contains mostly H2O and some EtOH so I figured add sodium Metabisulfate till saturation and quickly filter then add EtOH to precipitate the adduct but I want to make sure I got what I desire.

[Edited on 6-6-2010 by Sedit][/rquote]

Buy a cheap "white" decorating vanilla. Boil down with something to help exclude air until the fumes aren't flammable, or watch until the temp hits 100C. I topped the beaker with tinfoil and a pinhole to help with this. Then chill the mixture, as vanillin has a pretty steep solubility curve. You should get white to off white (off white more likely) needles forming- let it cool undisturbed and slowly or you get mushy fine crystals that trap the solvent- molten vanillin may also oil out as it has a low melting point out but should freeze.

I have NMR verification that (at least as of 4 years ago) Wilton's clear decorator vanilla was all methyl vanillin with no ethyl vanillin or other flavors (at least of the product as isolated above and recrystallized from boiling water).




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[*] posted on 6-6-2010 at 09:57


Thanks UC. I did a test tube run by adding "dirty" (ill explain in abit) Vanilla extract to Metabisulfate until no more would dissolve and filtered it. Upon adding more EtOH as expected the clear solution took a cloudy appreance and a fine white precipitate was noted but not isolated due to the small scale.

By Dirty I mean all kind of crap like glycols and sugers which I obviously don't want but its what I had on hand when i first decided to try it for the hell of it.

Im doing a small test as well along the lines of what you just stated and am evaporating the entire contents down to a syrup(more then likely) mainly to remove the EtOH and H2O then I was considering adding a .5:1:1 H2O/EtOH/Et2O mixture to dissolve the syrup and slowly allow to evaporate and see if any crystals form. If they indeed do I could adjust the ratios of the crystalizing solvents to get more bang for my buck. Indeed however I will search for the brand you made mention of because I want pure vanillin when im done just to say I did it.

PS: What about NH3 adduct, that should accomplish the same goal simular to how BnO is isolated forming the trimer and then a simple acid hydrolysis would recover my Vanillin correct. May be one of the simpler methods if proves true... No other way to find out:D Ill be right back , lol

[Edited on 6-6-2010 by Sedit]





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[*] posted on 6-6-2010 at 13:34


Nope not even the slightest bit of precipitate using (aq) NH3 although the R-OH contents in the mix may possibly be solvating the adduct but I don't know. Ill get some cleaner material tommorow and give your metho a shot UC.

I must ask. Whats the need to exclude air from the mixture needed for? Am I doing this just to remove the EtOH and allow the Vanilin to precipitate due to its low solubility in H2O or is there something im missing?





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"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story before."~Maynard James Keenan
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[*] posted on 8-6-2010 at 15:49


I made 500 ml of 0,1M (NH<sub>4</sub>;)<sub>2</sub>Fe(SO<sub>4</sub>;)<sub>2</sub> solution today by dissolving 19,61 g of the dry powder to 500 ml with deionized water in a volumetric flask. It is very old, however it had the characteristic blue color of Fe(II) it should have before I dissolved it. The solution, however, was more like a murky yellow. Now I'm seeing a brown precipitate, but not much.
Is this due to atmospheric oxidation or must it have been something in the water that caused it? Mohr's salt is said to be stable against air oxidation because of the acidic ammonium ions present in the solution.

Anyhow, would it be okay if I filtered off the fine precipitate and standardized the solution against 0,02M KMnO<sub>4</sub>? The permanganate is standardized against sodium oxalate, a primary standard.
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