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XeonTheMGPony
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exactly natural form with the y Pyrethrin, artificial with the e
y one is safe with cats, the synthetic how ever works the best.
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Dr.Bob
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I found a 1 lb bottle of DDT from ~1960 when cleaning my parents house out. I'll save it for emergencies, but nice to know I have an antique.
Fipronil is also quite toxic to bees, but for some reason it has been largely ignored in the press. It does work well on termites, which is useful.
I still find it a shame that Chlordane (which was banned for most everything years ago) was not allowed to be used still for termite control, as one
treatment would protect a house for 40-50 years, which is far longer/better than any other pesticide, and it binds very tightly to clay, so ideal in
the south, and it barely ever leaches out of the clay into water, so ideal for the South. They used Chloropyrophos for a while, which is incredibly
toxic to most living creatures, but it has a short half life in soil, and leaches in to water more. Now they mostly use fipronil, imidacloprid, or
hexaflumuron bait, all of which have pros and cons, but none lasts 50 years. All have different modes of action, so each works better in some
situations. Chlordane was both a repellant and a toxin, so termites stayed away from it, much like pyrethroids.
Another neonicotine analog of imidacloprid was Thiamethoxam, which uses a previously unknown starting material, (2-Chloro-1,3-thiazol-5-yl)methyl
bromide, which turned out to be a neat optimized synthesis, almost trivial, from several cheap chemicals, and the product is autocatalytic to the
reaction, so your yield goes up each time you use the same reactor. Sadly, China had already started selling copies of it on the black market before
it even got through the EPA, so I saw adds for it before it was even legal to use, and before the inventor could even start selling it legally. It
had been thought that the pyridine in nicotine was critical to the toxicity, but that proved incorrect, as several other heterocycles work.
Hexaflumuron works as a chitan growth inhibitor, so the bugs grow in their shell until they crush themselves as the shell cannot grow larger. It
makes a great bait, as termites spread it around, and it takes a long time to kill them, so they can spread it into the colony before it hurts them.
If you simply treated the sill plate of a house with it, you could potentially have a baited house that would kill all termites, but that would cut
out the pest control companies, so they did not like that idea. Since that wood is enclosed in the final house, it would not be exposed to any
insects other than those eating through the sill plate. But that still seems like a great way to avoid termites, without exposing the environment to
it. Termites cannot detect it, unlike treated lumber (which they avoid or go around in mud tunnels), so they would eat enough to kill the colony in
theory.
I guess you might be able to tell I was a chemist who had termite problems once... I found the literature hard to find and read, but eventually
realized that many of those compounds could be made readily but you had to understand how to use them to make it worthwhile. Fipironil is not very
easy to make, BTW, so I would try hexaflumuran (you can also buy it readily now) or just buy one of them mail order. It would be hard to make some
of the cheap enough now that the market is flooded with cheap Chinese generics, but this is one case where I am not worried about the quality of the
generic product. (I have seen photos of some Indian generic drug "factories", some of which had birds living in the roof or holes in the walls
allowing in rodents. Yeach.
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Tsjerk
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Quote: Originally posted by Tsjerk  | If I would run this synthesis again I wouldn't use an excess of bromobenzene again... I had the gut feeling it would evaporate quite easily, but it
seems to be quite persistent. I still didn't get it to fully crystallize and I suspect the bromobenzene to be guilty for that. I could pull I vacuum
but that would mean more dirty glass and more mechanical losses.
What I have now is a slush of crystals. The DCM seems to be long gone, but there is some liquid junk.
Maybe I will just poor boiling water over it, it might separate.
Edit 2: And I would use double the amount of sulfuric acid. The volume of product I have after evaporating for more than a day is almost halve the
volume of the oily liquid I had after first poring the reaction on ice. I guess there was to much water in the reaction, most preparations are done
with a bit of oleum and anhydrous chloral, although it should be doable with just 96% sulfuric acid and the hydrate of chloral.
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I ran the reaction a second time with twice the amount of sulfuric acid and a smaller amount of bromobenzene. I think I used about 2.025 eq.
bromobenzene compared to the chloral and 250 ml of sulfuric acid.
The yield still sucks (23%) and is comparable to the yield with half the sulfuric acid, but the product seems a lot cleaner. This time I just filtered
the crashed product and dried it. I boiled in about 100 ml methanol and filtered after cooling. The product seems more crystalline. The melting
temperature is somewhere above 100 degrees.
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Tsjerk
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I made an emulsion because I thought the evaporation method was a bit crude and a lot of Br-DDT was decomposing.
I dissolved a gram of Br-DDT in 20 ml of mineral oil with a bit of heating. With strong magnetic stirring I mixed this with about 30 ml of water and a
couple of drops dish wash detergent. I got a white emulsion that didn't separate, this was diluted to 750 ml, the suspension slowly floats up, but
never really separates, a quick shake suspends it again.
This mix in a plant spray works really well for dispersal of the Br-DDT.
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Tsjerk
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The emulsion works really well. Now and then I have some pest growing, mostly on new parts of plants or on new plants coming in. I'm still using the
gram of Br-DDT emulsion made in July. I really only have to spray once whenever I see something. After that it's gone.
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aromaticfanatic
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How did you acquire chloral hydrate? Where I live it is prescription only for insomnia and I haven't really heard of a successful synthesis of it so
far. I hear of people chlorinating ethanol but it seems like most attempts are just failures.
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Tsjerk
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I bought it from Mario.
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morganbw
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| Quote: Originally posted by aromaticfanatic | | How did you acquire chloral hydrate? Where I live it is prescription only for insomnia and I haven't really heard of a successful synthesis of it so
far. I hear of people chlorinating ethanol but it seems like most attempts are just failures. |
Look this over, I have not done this but this is what I would attempt if I were needing homemade chloral hydrate.
chloral hydrate synthesis
[Edited on 12/11/2020 by morganbw]
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Tsjerk
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I tried something different to dispers the DDT, I dissolved about 200 mg in petroleum ether, bp 60-80, and added that to about 200 ml water, a drop of
soap and a pinch of TBAB.
I don't know whether the soap and or TBAB did anything, but with strong magnetic stirring and heating until all PE evaporated there was a very fine
mist of white solid in suspension. Some of the DDT formed bigger crystals, and the fine solid very slowly settles, but a shake quickly brings it back
in suspension.
I now use this in a spray bottle. Only one annoying species of wooly aphid seems not to care too much about the stuff. But other than that no more
pests in my greenhouse. 1% ethanol is doing fine against the woolly buggers though.
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Tsjerk
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I ordered some chloral hydrate and fluorobenzene, more coming up! I already found OTC fluorobenzene some time ago. But when I just stumbled on over
the counter chloral hydrate I couldn't resist. I hope the one annoying wooly lice that can crawl over crystals of the bromo compound can't resist
either.
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karlos³
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You should have said something, I told you I have fluorobenzene when we talked about this, but maybe you forgot?
OTC fluorobenzene? 
That is weird, whats it used in for?
OTC chloral hydrate is also weird, but I guess its some fixation solution for microscopy or such?
Have you thought about adding a tiny bit of a non-biocidal(i.e. not a quat. ammonium salt) PTC agent?
Thinking of the tweens in that aspect.
Or maybe a different combination... we know that celite is harmless for plants as long as they are not buried under it.
But for invertebrates?
Apparently they react different to differenct qualities of celite, with the "edgyness" (couldnt resist) being what matters on their effectivity.
But they slice open their cuticula, all of them, just differently well, and that makes them for once prone for drying out.... but if you would combine
a finely powdered DDT analogue with celite...
Thats like walking on syringes full of lethal injections for them, I would imagine!
I mean, if I would be fucking armoured like a tank, I would walk over a pile of two tons of sodium cyanide and wouldn't even flinch the slightest bit
either.
But no matter how well armoured, I would not walk over a field of needle-like crystals of NaCN which could easily poke through my armour.
The insects though do not know that much.
Seriously, that might be a very good idea, this combination, as a dusting powder.
Celite is very effective, but combined with such a strong a poison?
Fuck your armour, wooly lice! 
verrückt und wissenschaftlich
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Tsjerk
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I forgot about you telling about the fluorobenzene, but I was ordering some other stuff from S3 chemicals as well, and it's wasn't very expensive as I
don't need much. Once I make some I can send you some of the F-DDT.
I don't know what the chloral is used for, but it comes from another online chemical supplier. But I was ordering some aromatic amines to make some
azo dyes and saw both toluidine and chloral coming by.
Celite is a good idea, I want to build a real greenhouse at my new place. But that is probably a project for after next summer.
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karlos³
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Yeah and you'll get some of the "original DDT" that a friend of mine has found among his chemicals 
We need to compare their activity with the original, and that mix with celite definitely needs to be tried too.
verrückt und wissenschaftlich
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Tsjerk
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Cool, I actually wanted to ask you if you have chlorobenzene, but straight DDT would be even better. I only read an article (2020) about F-DDT after I
ordered the fluorobenzene saying the F kind is probably only more effective in gas phase, not in contact.
So F-DDT sublimed and Cl-DDT on celite sounds as a good combo.
https://doi.org/10.1016/j.pestbp.2020.104686
Sci-hub.se
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Tsjerk
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F-DDT was made.
85% yield, not distilled, but it did crystallize.
20 grams of chloral distilled from chloral hydrate and sulfuric acid (equal weights) was mixed with 2.1 equivalent fluorobenzene and 50 ml sulfuric
acid to which 6 grams of P2O5 was added. This was stirred at around 20-25oC for 24 hours. The solid P2O5 dissolved in the mixture during
the reaction, but it never became clear.
After dumping in ice water and washing with water the sticky oil was diluted with a dash of DCM to get everything out of the glassware. This was
washed with brine.
After heating the almost colorless solution to 100 degrees for about 10 minutes to drive of the DCM and fluorobenzene the now thick oil was put in a
freezer at -18 degrees for a couple of days after which no crystallization occurred yet. Somewhere during the following days the oil did crystallize
upon standing at room temperature.
Next up is Cl-DDT.
[Edited on 22-3-2022 by Tsjerk]
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Tsjerk
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F-DDT works very well against ants. I have a back garden with mostly tiles and with the temperatures going up everywhere small heaps of sand appeared.
One of the heaps was right in front of the door and even on top of a part of the doorstep.
I took some of the sand and swirled it around in the not cleaned container I used to crystalize the F-DDT and put the sand back where the ants were, I
guess containing a couple hundred milligrams of DDT. Next day all ants, also on the far side of the garden were gone. Now five days later there are
few ants remaining on the far side of the garden, but they are visibly slower then normal. I'm sure that if I would treat the whole garden they would
all be gone.
I wonder whether the ants that survived did so because there was too little DDT or because they are resistant. We will see how they respond after
having recovered from the first treatment. Apparently fruitflies have some resistance genes which allow a few flies to survive after which the
resulting population becomes completely resistant.
[Edited on 27-4-2022 by Tsjerk]
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Fantasma4500
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my idea might be too simple to work: gas them?
plants cant take a atmosphere of pure CO2 but they can live in quite high % of CO2
removing the oxygen might be difficult
does carbon monoxide damage plants?
maybe unload a bunch of ammonia in there
maybe methanol+boric acid burning off could deposit a bunch of boric acid throughout the room that would then kill the buggers- no idea how boric acid
impacts plants
if it was just a simple mold, having ammonia and HCl fumes react with each other should form a thick smoke of ammonium chloride which would eventually
settle everywhere, and that could then kill them by osmotic pressure
maybe a solution of ammonia could work?
maybe get some small creatures that eat bugs
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Tsjerk
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Sure, I'm going to gas my garden with carbon monoxide or drown it with ammonia/methanol when I have a selective insecticide that is active in a range
where I only have to use a couple hundred milligrams on one spot in the garden.
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Tsjerk
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I have made some Cl-DDT, 42% yield after recrystallization from IPA. I used the same procedure as for the fluor analogue.
I wondered whether there would be more DDT in the left over IPA so I boiled it down, but what precipitated was a sticky mess. Probably a mixture of
ortho-para and ortho-ortho isomers.
I'm thinking about trying to recrystallize some of the F-DDT, although what I have has a melting point of around 28 degrees (lit. 44-45). The melting
point of o,p-DDT (chloro) is much lower than that of the p,p, 76 against 108 respectively. I can't find the melting point of o,p-DFDT, anyone can?
On the other hand, I can imagine the fluor to be much more para directing therefore explaining the higher yield I got when making the fluor analogue.
Update on the ants: apparently when you treat one of the heaps the ants will carry the poison to the queen and when she dies the whole colony does.
The ants never came back and only ants spreading from neighbouring colonies were seen until today.
[Edited on 28-6-2022 by Tsjerk]
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Tellurium
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Bromo-DDT using Chlorosulfonic acid
I sucessfully synthesized Bromo-DDT recently. I used Chlorosulfonic acid and chloral hydrate:
To 4.10g of Chloral hydrate 1.7ml of chlorosulfonic acid was carefully and slowly added with stirring. The temperature is kept betwen 0-20°C using an
ice bath. After 15min of additional stirring 7.9ml of Bromobenzene is added. During the addition the whole mixture turns slightly pink. Additional
1.8ml of Chlorosulfonic acid is slowly added. This time the addition is much less exothermic. The ice bath is removed and the reaction is stirred at
room temperature for 6h. During this time a lot of crystals form and the pink color gets much stronger.
10ml of water is added, which will immediately make the pink suspension completely colorless. This is vacuum filtered and washed with water. After
drying in vacuum 7.94g (72,8% of theor.) colorless crystals are obtained. Although the product looked great already it was recrystallized from hot
ethanol to give 4,12g of fine, white needles in the first crop and 0,86g in the second crop. Total recrystallized yield is 4.98g or 45.7% of the
theoretical yield.
1H NMR (300MHz, CDCl3) δ = 7.35 - 7.19(m, 8H), 4.80 (s, 1H)
The NMR-Spectrum is attached as PDF File
 
Attachment: Br-DDT.pdf (19kB)
This file has been downloaded 161 times
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Tsjerk
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Very cool! Especially the NMR! Could I send you some of the Cl-DDT and F-DDT I made?
My Br-DDT is probably worse than the stuff you made, but my Cl-DDT should be quite pure. My F-DDT is what I'm wondering about the most.
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Tsjerk
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I saw the same red color when I used P2O5 btw.
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Texium
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If you're able to ship to the US, I wouldn't mind running NMRs of your compounds. I also wouldn't mind trying them out on the ants that are always
trying to invade my house!
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Tsjerk
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| Quote: Originally posted by Texium | | If you're able to ship to the US, I wouldn't mind running NMRs of your compounds. I also wouldn't mind trying them out on the ants that are always
trying to invade my house! |
Hi Texium, thanks for the offer! But Tellurium is closer by and able to run the NMRs.
If you want a gram of the three, I can send them to you no problem if you pay for shipping. I would be interested in the experiments you could with
them. Especially a gram of the Cl and the F should last half a lifetime  when your
garden is small.
[Edited on 2-9-2022 by Tsjerk]
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