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Questions for Lestat: Lestat's Lab

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Lestat:
Just accidentally stumbled upon a neat little recrystallization process, and potentially even a means of salvation for things that otherwise would be way, way beyond redemption. Hell this might even be usable to recrystallize Theresa May :autism:

Started with something, muck and tar, polymerized crap, in a small 3-neck RBF (about 50-75ml, in 24/40) and after dissolving what started as a small wad of khaki tar, looked like a dried out piece of phlegm hawked up by an oyster with severe cystic fibrosis; and left to dry on desert rocks for several months.

Thought it fit only for getting it the fuck outta my nice shiny glass treasures, and part dissolved, part  suspended it in methanol, and then meaning to add some warm water to shake it up in accidentally took my eye off the kettle, so boiling hot water went in (the original compound is completely insoluble in water) instead.

But what happened? the boiling water flash-evaporated the methanol, and deposited a nice big clump of yellow (the original compound is bright yellow and takes the form of needle shaped crystals of water-insoluble, alcohol-soluble material) crystals, all fine needle like fluff!

With a really sharp as shit dividing line between truly redemption-proof utter total Theresa May, and the cloud of fine fluff deposited above.








I think I'm going to try and develop this into a useful recrystallization technique for more general use, different substrates, solvents etc. Just as long as the substance is highly soluble in a low boiling solvent and insoluble even at heat, in a second, higher boiling solvent.

Lestat:
Haven't tried this yet, but I just by chance found this publication by a member of sciencemadness.org, an unusually facile synthesis of the versatile reagent, sulfur trioxide, the acid anhydride of sulfuric acid, SO3. Usually a rather difficult reagent to synthesize, and definitely dangerous to handle, being an extraordinarily powerful dehydrating agent, violently, explosively reactive with even small quantities of water. Useful for making dimethyl sulfate, diethyl sulfate and similar dialkyl sulfates, potent alkylating agents, via reaction of dialkyl ethers with sulfur trioxide. And by reacting SO3 with sulfur dichloride, SCl2, the extremely valuable reagent, thionyl chloride, which is watched by three letter agencies, if you get what I mean, to some degree, too much for my liking. Oh boy, SOCl2 is JUST the sort of reagent I'd absolutely love to be able to make myself, thats making it look accessible for DIYing with the sulfur trioxide synthesis. Oh this is NIIICE.

And I can make the SCl2 at home I should think, without too much difficulty by chlorinating sulfur powder with Cl2 gas, and fractionally distilling the product to separate out the disulfur dichloride, any sulfur monochloride etc. and saving those for other uses. Still useful, for chlorinating things amongst other things. Plenty of delightful sulfur halide chemistry to be had there. But SOCl2 is the REAL prize amongst sulfur/halogen chemistry. And thionyl bromide would be even MORE useful to have as well, because the bromide anion is a better leaving group than chloride,  so could perhaps improve the yields where the halide is just being used as a leaving group to stick some nucleophile on there in it's place. As well as making acyl halides, alkyl halides (the alkyl bromides would give a higher yield generally than the corresponding alkyl chlorides, probably not matter too much with acyl halides, carboxylic acid chlorides are reactive enough as they are, reacting really rapidly).

http://www.sciencemadness.org/member_publications/SO3_and_oleum.pdf

Reading this atm. Found a finished writeup for hydrazine synthesisl synthesizing it from urea via a ketazine. Urea is cheap as shit, and generally speaking not the most exciting chemical in the world. But, hydrazine on the other hand, N2H4, a relative of ammonia, although much more 'excitable' so to speak, very useful reducing agent amongst other things. The freebase of hydrazine is volatile, and highly dangerous, but this route furnishes the sulfate salt, which can be stored far more safely, and hydrazine freebase generated in-situ and distilled into a reaction mixture or solvent for addition to a reaction mixture, outside and wearing a gas mask and full protective gear due to its severely toxic nature Urea.....made exciting. Damn. But nicely stored as the sulfate salt, a crystalline solid, which can be deprotonated with KOH or NaOH and the hydrazine driven off and dissolved in a solvent, carefully.

Since, hey, who wouldn't want to have hydrazine on tap :autism:

Just starting from high-purity urea, a little gelatine to bind trace transition metal ions and trap them, safely sequestering them away from the reaction where they would foul up the reaction and potentially completely fuck it up, MEK (methyl ethyl ketone, a common solvent similar in nature to acetone, often use for cellulose thinners), sulfuric acid and sodium hydroxide, as well as strong sodium hypochlorite, which I happen to have a huge glut of, more than I'll use in a bloody looooooong time, after going on a late night/early morning random walk one sleepless night and just happening to chance upon a rather large drum of industrial strength hypochlorite, of just about the strength demanded for the hydrazine synthesis.

http://www.sciencemadness.org/member_publications/hydrazine_sulfate_ketazine.pdf

I think I just found a couple of new projects that should provide me with a good challenge, and endless fun and especially in the case of the sulfur trioxide synthesis, finally, the access to SO3 needed to produce my OWN thionyl chloride  and thionyl bromide. Fuck....Ing...SWEEEET :heisenberg:

Although I do have another project that takes precedence, or shall do once I can obtain some  nitromethane. I need both nitromethane and  nitroethane for it, for something special, and very, very rare, that as far as I  can tell has possibly never even been synthesized, that will tax my skills in microscale chemistry, for I need to get definitely two, and  possibly as many as four end compounds starting from just 5g of a rare, precious, DAMN difficult to obtain and most unusual starting compound. I have that, although at considerable expense, nearly £100 for the 5g I have to work with. I have the nitroethane, but no nitromethane left. I'll only need a few milliliters, but I do have plenty other uses for nitromethane, so I'll probably grab a 5 or 10 liter can of the stuff. Will need some specialist, very mild and selective hydride type reducing agents, something that won't abstract the bromine atom from an phenyl bromide, whilst reducing an aliphatic nitro paraffin group and an aliphatic double bond, both at the same time. Considering looking into Red-Al, aka vitride, as the reagent I'd otherwise use for the nitroalkene reduction to the aminoalkane, Lithium aluminium hydride, has considerable potential to rip that bromine atom right off the aromatic ring, which considering the tiny quantity of the starting compound available to me, its huge cost, and the fact I need to stretch it into at least two, more likely four different products, maybe ending up with just half a gram of end product, a gram of each if I am both fortunate, work with a light touch, and great care, just enough for the tests I need to perform plus characterization of the melting point, and thin-layer chromatography analysis to determine RF values, although for the TLC and melting point analysis that won't take anything worth note, even for such delicate work, as I'll only need a few milligrams for each test, although running the MP tests still needs to be done for each target compound in triplicate, it takes only a few tiny little crystals sealed  in a glass microcapillary tube, and slowly heated in the oil bath of a Thiele tube.

I've even had to buy some glassware specially for these syntheses, such as a Buchner funnel of the type with a glass frit, in this case of small capacity, just 30ml, and with a tall, narrow profile rather than squat and wide, and in this case, having a frit with an upper porosity size of just 5 microns. Which of course means gravity filtration is out the window completely, and I'll be filtering it under vacuum, the Buchner having a 24/40 ground glass joint with a vacuum hose barb on the side to  hook it up to a vacuum  line, the frit is tiny, meaning my precious products will be nicely confined on a frit a little less than just 30mm wide, and of such  fine porosity that the tiniest crystals will be collected and retained. So fine, in fact that even bacteria will be stopped from passing through the pores of the frit.

Had to buy it specially, and at not inconsiderable price, cost me over £50 for the one piece of glassware. And I have a small (100ml or so) 3-neck flask just for the purpose. Actually I may even work with my 10ml micro-scale round bottom 24/40 flasks, or something like a 50ml RBF for the filtration, and will be using the absolute latest bleeding-edge technology for synthesis of the intermediate between starting material and the nitroalkanes (plus catalytic base, in this case something rather special, an ionic liquid catalytic base, that has  been known to give almost stoichiometric yields for other, much more commonplace instances
of the same overall field of chemistry, which I'm not altogether inexperienced with, although the ionic liquid base catalyst will be entirely new to me, so I'll test it with both completely non-precious intermediates of the same overall chemical type, and reactions first, as well as some more precious by far, but obtainable
materials, more exotic, but I want to build up a library of tested intermediates of the same overall structural patterns, just with different substitutions on the phenyl ring than the bromine atom in the unusual position it is located in, one nigh totally unexplored in scope for electron-withdrawing substituents such as halogens, cyanide groups, nitro or trifluoromethyl groups, and also another oddball, a difluoromethyl ether. Going to be quite some fascinating and very novel research indeed, quite possibly a first, and almost certainly a first-in-man trial of the end products, two of them certainly, although whether I can squeeze all four desired compounds out of that 5g of intermediate....oh boy, it'll be taxing work on such a delicate material on such a tiny scale, but I'm going to thoroughly enjoy myself doing it :heisenberg::autism::heisenberg:

Can't WAIT to grab some nitromethane so I can proceed. Tempted to do the half of the work with nitroethane first as I have it, but no nitromethane. But, the starting material is air-sensitive too, just to make things more challenging and difficult, although perhaps even if oxidation does take place can salvage it, by reacting the resultant substituted benzoic acid with thionyl chloride and then reacting the resultant benzylic acyl halide with sodium azide followed by reduction of the arylalkyl azide in mild conditions to afford the desired amines. In fact I might even use that route, but first, I'll stick to what I know, albeit at the cutting edge
of synthetic procedures, where I'll have the added bonus of broadening my knowledge and  capabilities. Because hopefully this, the ionic liquid catalytic base will be an improvement over even the microwave irradiation-based route that I've been using for this particular type of synthesis with other starting materials, which is very, very fast, and gives a quite pure product in better yields by far than the old route using conventional heating, this I should be able to run at room temperature, under inert atmosphere and with degassed, then argon-sparged solvents.

Then, after that, maybe I'll let my hair down a bit and work on sulfuric anhydride (sulfur trioxide) synthesis, production of oleum (concentrated  H2SO4 with additional dissolved sulfur trioxide, known as oleum, fuming sulfuric acid, or to use the archaic nomenclature, fuming oil of white vitriol) and on hydrazine synthesis via the ketazine  process, using gelatin to bind trace levels of transition metal ions which otherwise would throw a spanner in the works and lead to my getting back dick all. Still, caustic soda, sulfuric acid, urea, methyl ethyl ketone, hypochlorite, nothing there is  precious or super rare or hard to get, all commonplace starting materials. I'll treat myself to a brand  new flask  for it though, one I know has never, ever been treated with sulfochromic acid etch to strip out crap, as the Cr (VI) used, even in traces, would probably result in it's interference with the hydrazine synthesis using the ketazine route. And the urea I'll use, I'll have to buy some near analytical grade urea, of super-high purity and specifically trace metal ion free.

Lestat:
Sometimes it feels like a citizen chemist's work is never done...

Currently sat up on the sofa at nearly 20 past 2 in the morning, working on spreadsheets. At least though I've got some amusing and very politically incorrect cartoons on TV, family guy, american dad and then...bugger, whats it called....something that comes on even later than that, about a racist US border patrol agent and his white trash family and mexican next door neighbor, 'bordertown' Ithink it's called.

While I work on these, been drawing up a series of spreadsheets; charting the potential precursors for a specific compound, then the different intermediates from them, and the various different routes from the intermediates and finally methods for reduction to the target compound.

This being the main spreadsheet, then there are to be  separate ones for each intermediate, for example one for ketones, which would include for instance, ketoxime formation using hydroxylamine hydrochloride with sodium acetate to deprotonate it in-situ liberating the  freebase NH2OH, which reacts to yield the ketoxime, followed by Bouveault-Blanc reduction of ketoxime to primary amine (one does this by dissolving the substrate ketoxime in RIGOROUSLY anhydrous ethanol, and then adds the calculated quantity of sodium metal, which previously has been cut up into little pellets, slowly, carefully, into a well-stirred flask supplied with an atmosphere of dry argon gas, which in my case  I get from the welding supply store in disposable tanks and just bubble it through some concentrated sulfuric acid in a Dreschel bottle to scrub any remaining traces of water. The  argon serves as an inert atmosphere to prevent any unpleasantness on the part of the  sodium metal, which of course is well known for being rather feisty stuff)

And also, from the  ketone, reductive amination methods, including  aluminium amalgam made with Al foil and  mercuric chloride, in various media, not a method I like due to the Hg and  it's touchy ass nature generally. But Al/Hg plus either  an alkylamine or a nitroalkane which is reduced to the alkylamine  in-situ to reductively aminate the ketone and furnish a secondary N-alkylamine.

Likewise, forming an imine, with the amine  and the ketone whilst simultaneously removing the formed water which would otherwise hydrolyze the imine; such as  with molecular sieves, or the use of a Dean-Stark trap, and reduction of imine to secondary amine, AFAIK sodium borohydride ought to be  able to reduce the imine,

Could get the ketone either by dry, pyrolytic destructive distillation of the calcium or the lead salt of an arylcarboxylic acid, or by running  a Knoevanagel, a type of nitroaldol condensation, in the microwave, between the desired appropriate aldehyde and  a nitroalkane, to give a nitroalkene. And this, if  then reacted with a combination of fine iron powder,  a catalytic quantity of ferric  chloride hydrate, in either concentrated hydrochloric acid or glacial acetic acid at 80 'C for  3-4 hours, will furnish the desired ketone.

If the same acidic iron/ferric chloride reaction is used however, AFTER first reducing the  nitroalkene produced  by the Knoevanagel once  that has finished  being nuked in the microwave oven (sounds  weird I know,but it works fantastic in the microwave) using sodium borohydride in four-sixfold excess with respect to the nitroalkene, it gets reduced to the nitroalkane, the excess borohyde being used in order to suppress a parasitic side reaction, namely Michael addition between the nitroalkene starting compound and the formed  nitroalkane, the  high quantity of NaBH4 used, along with adding the nitroalkene in solution into a solution of NaBH4 in isopropanol helps prevent  the Michael addition and polymerization to tarry garbage, if this is done, one gets the nitroalkAne from the nitroalkEne, and then the same iron dust/ferric chloride/hot acid reaction reduces the nitroalkane to the corresponding end target option of the corresponding primary amine.


So I'm basically working on a summary of known routes, known  starting precursors and from these, known intermediates, and what can then be  done with said intermediates,eventually encompassing a separate spreadsheet for each intermediate, reaction conditions-sets and yields which accompany them when done at fr.ex different temperatures, for different times, various solvents, catalysts etc. so I can then  use it as a reference to pick the best options  for me according to what is available, what of the available techniques and materials is most  desirable and expedient, and what adaptations with what yields I can expect.

As well as  methods of making the different precursors and  intermediates, and  from what. Such as in one case, the  aldehyde to nitroalkene route, if unable to purchase reagent grade materials, the essentials can be distilled from certain nail varnish strippers and a kind of paint stripper, along with a catalyst prepared from something extracted from a type of epoxy resin curing section and some acetic acid, plus a microwave oven.

Plus either manganese dioxide from batteries, or certain chromium based  oxidant reagents such as the Collins, Jones, Etard or Sarett oxidations on the ingredient extracted from the paint stripper.

Thankfully though  for me at least I both already have the reagent grade materials, and am  able to purchase more if and when I end  up needing them.

Been wanting to experiment with using a nanomaterial reduction catalyst, based on copper  metal, produced in a super-fine state of division, a few tens of nanometers per particle at most,  in combination with borohydride, in order to directly reduce the nitroalkane to the primary amine which is one of the desired targets.

Ah well...back I go,  nose to the grindstone, no rest for the wicked as they say  :heisenberg:

As I've got to do the spreadsheet set by hand, taking quite some time and  effort.

Think I'll make myself a big steaming bowl of hot porridge, with salt, butter and brown sugar melted into it, then covered with brown sugar as  a topping
and then get back to work.

Lestat:
And hopefully, since I've just discovered a little test batch of one of those starting materials, the one that I'd make the intermediate upon which it would be put to use, I might even find the time, after fortifying myself with said big bowl of brown sugared porridge, a few lines of oxy and a hot cup of a rather nice white leaf tea, to prepare some copper nanoparticles and put the system to the test again.

Lestat:
Just got to strip the metadata out of the files...then...

Here is a quick view and rundown of how I run melting point tests, one measure of purity for solid materials, as in the majority of cases, the admixture of a given substance with another substance, an impurity, often as not, depresses the melting point. The greater the degree of depression compared with either a known, published melting point, or else that of one which is first carefully recrystallized multiple times, and where possible, also vacuum distilled, cutting the fore-run off and putting that back in for re-purification, until one has both a sharp boiling point, or range of a couple of degrees 'C, and likewise, when it melts in a capillary tube, the melting point being nice and sharp is another good indicator that the purity is good.

And, running chromatography, either paper chromatography for initial coarser inspections, or for when things need the finer detail and more discerning eye, using thin layer chromatography plates, using multiple solvent systems to slowly push a mixed solvent front moving through a finely divided stationary phase bound to a backing such as metal foil or glass, and separate constituents of a mixture by virtue of their differing polarities, charges, molecular weight, affinity for the substrate and the solvent systems employed, causing them to move at different rates when contacted by the moving solvent front, and developed by means such as iodine fumes, reagent sprays which cause a color change like ninhydrin, some can be visualized via UV fluorescence, and of course others are coloured. Different spotting patterns tell one what is in there, and one can follow reactions in progress using TLC (thin layer chromatography) also.

Anyhow, this is a melting point test setup.

The piece of glassware that looks like a large boiling tube with a sideways-oriented V-shaped tube forming a triangle, is a Thiele tube. It's used by strapping a microcapillary sample tube containing a sample one wishes to test the melting point of to a thermometer, using something like a couple of little thin wire ties like the sort used for sandwich bags, etc., or an elastic band.

The Thiele tube is then filled with oil to a level that is above the height of the top arm of the sidearm tube and the thermometer placed in, so that the sample is around the middle of the V, which is present to ensure even and slow heating, the V itself being heated at the end, so that convection currents heat the oil evenly and steadily, so the melting point is obtained neatly and precisely.

The other photos show the filled, sealed sample tube. And unprepared tubes

The one with the rounded end is the prepared one about to be employed to run a test, one end fused closed with the flame of a torch, rotated between the fingers to avoid the glass bending, and after cooling, the open end dipped into the material to be tested, and poked down with a thin little flexible carbon fiber whisker, originally gotten off my old man, who got some for making floats, but found them not to his liking, so I've got some now which make fantastic sample tube pokers, as they are long, really thin and flexible, but tough. The internal diameter of the tube is only some 1-1.5mm at most, on the lower end is more like it.

A group of unprepared, empty tubes, unsealed, are shown also.

Just give me a few, to forensically sterilize the image files, remove GPS tagging data and the like and upload them to an image host, while I edit this in progress.

First-Thiele tube. This is a bit different to the usual, as mine has a ground-glass joint at the top, which is uncommon, but handy. For things like keeping the thermometer in place with a rubber bung with a hole drilled in it to accommodate the thermometer snugly or attaching other glassware. 24/40 joint size, same as most of my non-microscale glassware kit.



Second-filled microcapillary tube, after the bottom has been flame-sealed shut. I won't say in public what is in there, but as to the colour, yes, it is meant to be yellow.



Lastly-unused, unsealed tubes, length, 75mm, soda lime glass. Internal diameter hard to measure but about 1mm-1.25mm, 1.5mm at most.

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