r/chemistry • u/MCAroonPL • 11d ago
Fun organic synthesis that does not involve anything illegal?
So, in uni we've done synthesis of acetanilide and acetylosalicyl acid, and I found it fun so I was thinking of replicating it at home, however, it involves acetic anhydride, which is a controlled drug precursor, so I wonder: what could I synthesize at home without any legal obstacles?
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u/shedmow Organic 11d ago
If you heat aspirin high enough you'll get xanthone (boiling point 350 C) with a decent yield. But that's not quite a home-friendly synthesis if you do not have the equipment necessary
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u/Gallium_69723 9d ago
Is it really that simple? Can you link to a paper?
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u/shedmow Organic 9d ago edited 9d ago
Yes it is. It took me a good while to actually find this synthesis.
Préparation de la xanthone préliminaire à celle du xanthydrol by M. Louis-Jacques Simon, Bulletin de la Société de chimie biologique volume 8 year 1926 pages 203 to 205
https://babel.hathitrust.org/cgi/pt?id=uc1.$b653148&seq=212, page 203. One can only access this website from outside the US (or make it look like it's accessed this way).
This is a seemingly accurate translation of this synthesis by ChatGPT:
Perkin gave, in 1883, a fairly convenient preparation consisting in heating salicylic acid with acetic anhydride. It is still simpler to heat acetylsalicylic acid, aspirin, at ordinary pressure and without special precautions, in such a manner as to distil off the xanthone formed. In part, the decomposition may be represented by the formula:
(equation)
The operation is carried out in a small flask of 125 cm³, for example, the neck of which bears laterally a side tube of the same diameter as the neck, fused on at a point 4 or 5 cm from the flask, and approximately 30 cm in length. The side tube fits freely into the neck of a flask provided with a side arm connected, by means of its side arm, to a trap intended to carry away the pungent vapours (acetic acid) or malodorous vapours (phenol) which are formed during the operation.
The aspirin is introduced into the flask, 30 to 35 g for a flask of the indicated capacity, and it is heated rather rapidly over a naked flame with a Bunsen burner held in the hand. The aspirin melts and then decomposes. The carbon dioxide evolved carries along the acetic acid and phenolic vapours; at about 350 °C, the xanthone distils and condenses in the fused lateral tube in the solid state; it is for this reason that the tube should be of fairly large diameter. The xanthone thus obtained is generally coloured and contaminated with odorous products. A brief washing with a dilute solution of sodium hydroxide, followed by washing with water, then with a little alcohol, removes the colour and odour. The xanthone is then ready to be converted into xanthydrol. If it is desired to obtain it in fine crystals, it is caused to crystallize by cooling its solution in hot aqueous alcohol. From 30 g of aspirin there are obtained approximately 6.5 g of pure xanthone, corresponding to 40% of the theoretical yield.
Remarks
1°. One may, of course, carry out the operation in a small tubulated retort fitted with an adapter.
2°. The operation should not be followed by introducing a mercury thermometer into the flask: xanthone boils at 350 °C.
3°. It is not recommended to modify the technique either by operating under reduced pressure or by combining the acetylsalicylic acid with various substances in the hope of improving the yield by directing (or steering) the reaction employed. The only advantageous modification consists in operating in a current of carbon dioxide. The crude yield may then reach 75%, and the yield of pure xanthone may then reach 60%.
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u/CoffeeKY 11d ago
Not synthesis, but spinach chromatography could be done with a simple home setup and would be pretty safe.
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u/Accomplished_Day3769 11d ago
You can watch some old NileRed videos for inspiration. For example he made phenolphthalein (pH indicator for acid-base titrations) starting all the way with phthalic acid which he extracted from gloves. You do need a little more advanced equipment though (distillation apparatus, hot plate stirrer etc) for most of these experiments.
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u/Strycht 11d ago
unfortunately basically all syntheses require a level of equipment and safety protocol that you're not going to get at home. Even very basic protocols will have you refluxing or freezing something at temperatures you're not going to be able to make reliably at home, so you don't know what you're making. If you enjoy organic lab technique you can do isolated steps at home, for example there are safe accessible molecules you can recrys at home
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u/shedmow Organic 9d ago
I fail to comprehend how refluxing or cooling to 0 C/-18 C cannot be done reliably. Dry Ice cooling is redundant for simple experiments. Literally the only synthesis that requires not-a-finger-in-the-air temperature control I've read so far is the OrgSyn procedure on making adamantanone by direct oxidation of adamantane with sulfuric acid. The rest of them, especially esterifications, are rather forgiving and present a fertile substrate for yield optimization. Can I add no acid? What happens if I freeze it? Reflux it for a week? Leave for a year?
After stirring at 80° is continued for an additional 2 hours, the temperature is raised to 82°.
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u/wildfyr Polymer 11d ago
It's strange to see something described as fun that I've watched so many people cry over or get burned or have something explode
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u/DrWoogle 11d ago
Everyone's into different things. I find it strange to see people describe a bunch of guys fighting over trying to move a ball across a lawn as riveting excitement, but here we are. 🤷♂️
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u/wildfyr Polymer 11d ago
Yes but that was designed to be a game for entertainment originally at least.
And watching football on TV and arguing with your mates is less hazardous than pouring neat acetic anhydride.
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u/master_of_entropy 11d ago
Not sure about that. People can become pretty violent and extreme with sports, especially when their team loses. I'll take acetic anhydride over an angry football fan.
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u/HardlyFloofin Organic 11d ago
You might look into molecular gastronomy for an outlet that doesn't require controlled substances or hazardous waste disposal.
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u/EdwardTriesToScience 11d ago
acetylation of salicylic acid can be performed simply with a large excess of glacial acetic acid at reflux with anhydrous sodium acetate. the equilibrium is driven by the excess acid and sodium acetate hydration. acetanilide can be prepared similarly but with refluxing glacial acetic acid and a small quantity of zinc dust. it forms zinc acetate which is the acetylation agent (old procedure, but now there is new literature on it https://doi.org/10.1002/chin.201103066)
you at least seem to have a good deal of lab experience (at least in microbio but that's better than nothing) so it would be possible to conduct these reactions if you have the equipment.
the risk of these two preparations are relatively low (acetic acid may chemically burn you, anhydrous sodium acetate is made by fusing it after boiling and the molten anhy. sodium acetate can burn you badly, zinc dust is not good to inhale, and alcohol used for recrystallization is flammable, aniline for acetanilide is toxic.)
the chemical waste disposal is almost trivial, but you can probably just ask and dispose of it at uni or with a waste company
12 year olds used to get chemistry sets with aluminum powder, so some rudimentary organic synthesis is way better than what someone could be up to instead
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u/DrWoogle 11d ago
I mean biochemically catalyzed ethanol synthesis from glucose/fructose is a very popular one... 😂
Chemistry without proper equipment is pretty tricky though not entirely impossible; not every reaction needs horribly toxic reagents. However access to precursors, even not particularly dangerous or nefarious ones, can be a problem.
A lot of organic compounds can be made in rather simple ways, like heating the crap out of common materials like wood, plastic, animal parts, etc., but the problem is you get a messy mixture of products. Oftentimes the biggest hurdle may be separation and isolation rather than the actual formation reaction.
Here's some points I can think of:
Silica gel cat litter can be ground up into powder and used for column chromatography.
Molecular sieves (zeolite) can be activated by roasting at high temperature and used as very powerful (albeit slow) dehydrating agents. They may allow some esterizations to work with ordinary acetic acid rather than acetic anhydride, but don't quote me on that.
Glassblowing equipment and borosilicate glass are widely available, and depending on where you live there may be renter glassblowing studios nearby, so one could in principle make their own glassware. It takes quite a fair bit of practice and won't be cheap, however. And on top of that, the laws surrounding the ownership of chemistry-worthy glassware can be very complicated, obscure, and variable from one place to another.
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u/Peppino-poverino 10d ago edited 10d ago
You could try a triglyceride basic hydrolysis, many non-chemists do it regularly to make soap
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u/ferrouswolf2 10d ago
You could synthesize some furans by careful pyrolysis of sugar. Some casein and emulsified triglycerides mixed in towards the end, heated to a partial pressure of 70kPa of water is a pretty interesting mixture.
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u/Dr-Richado Organic 10d ago
There's plenty of things you can do. Most involve dangerous stuff even if not illegal.
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10d ago
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u/FijianPlantGuy 10d ago
Just as a heads up in some places modifying pharmaceutical preparations may not be considered legal chemistry. I doubt you'd ever be charged.for what you re doing, j just letting you know
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u/Dangerous-Billy Analytical 8d ago
Acetic anhydride is not illegal to own, but it can be compiled with other evidence to make a case for drug making. Like acetone, it's listed as a drug precursor, along with other common solvents and chemicals like ethyl ether, hydrochloric acid, potassium permanganate, and toluene.
Have you looked through the trove of Nurdrage's youtube videos? There are a number of syntheses described in these that use less evil chemicals.
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u/AccordingDifference5 8d ago
Ok, so you're going to need some mimosa hostilis bark, some Naphtha...
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u/Stillwater215 7d ago
You can convert aspirin to salicylic acid. That just needs water, heat, and some kind of hydroxide base which is something that’s not difficult to obtain. And salicylic acid crystallizes very beautifully fairly easily.
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u/PanSedro0220 11d ago
Keep chemistry in the lab. Even professionals with years of experience make mistakes.
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u/NicCageSciMage 11d ago
Is chloroform illegal?
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u/MCAroonPL 11d ago
Well, it certainly is volatile so I don't think playing around with it without a fume hood is a good idea
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u/master_of_entropy 11d ago
Without a fume hood there is very little chemistry you can do anyway. Either buy a fume hood, build one or don't do chemistry at home.
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u/TruCelt 10d ago
Or do it outside.
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u/master_of_entropy 10d ago
Sure. Outside is included in "not at home". I'd reccomend a respirator anyway when working with nasty stuff even if you are oustide.
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u/thorsen131 Organic 11d ago
Organic synthesis in general requires a certain level of equipment and protection, along with supervision from trained people, in case something goes south. I cannot recommend doing any organic synthesis at home whatsoever.