Sciencemadness Discussion Board - Bromo-DDT, p,p-dibromo-diphenyl-1,1,1-trichloro-ethane

Bromo-DDT, p,p-dibromo-diphenyl-1,1,1-trichloro-ethane

Tsjerk - 6-2-2020 at 02:02

I have a nice assortment of plants in my house, off which many in an indoor "greenhouse". I had a spare space, enclosed between two walls, with a big window on the south in my apartment. I build a frame of wood with aluminium corner strips all around where I could glue in Plexiglas.

Before building this greenhouse I already had problems, mainly with aphid. I tried everything against the buggers... spiritus with green soap, pyrethrum, pyrethrum with some aphid stress pheromone that should make them come out of there hiding place, lady bug larvae... nothing got rid of them completely. I have them under control now, but I fear coming summer.

My plants outside where fine after one spray with the spiritus/soap, but that was probably because within minutes there were dozens of wasps around to pick up the peaces. Indoor? Not to much. I even cut of my chili plants, because they were infested and on the brink of dying. They are starting to grow right now but the aphid are popping up again... in February winter.. little buggers.

So, then, lets take drastic measures: DDT. or actually the bromo analogue. I would have preferred the fluorine analogue, but I thought that was a bit expensive, and I could get a nice batch of bromobenzene, which could later be used for other experiments a bit easier than chlorobenzene. The bromo is about 20 times less toxic to insect compared to the chloro, but chloro-DDT is so extremely toxic, that shouldn't be a problem.

It is quite easy:

Chloral hydrate (25 g, 0.151 mol) was dissolved in sulfuric acid (96%, 125 ml) and bromobenzene (50 g, 0.318 mol, 1.05 eq.) was added. This mixture was stirred with a magnetic stirrer for 24 hours.

The reaction mixture was poured in 500 ml of crushed ice in water. The white water emulsion on top was discarded and the yellow bottom organic layer was seperated in a seperation funnel and stirred with a brine solution. The organic layer lost the yellow color and turned into a suspension of white crystals in a colorless oil.

The suspension was filtered through coarse anhydrous magnesium sulfate. the filtrate was a clear oil which formed white crystals on the top upon standing. The magnesium sulfate was washed with little DCM and the filtrate was pooled with the oily filtrate from before. The DCM is now being evaporated of under a draft of air on a magnetic stirrer.

A little of white crystals were scraped from the side of the container and was suspended in boiling water. An unknown substance separates as a liquid and floats on the water. The water was poured of and a white solid with a melting point above 100^oC stayed behind.

About 50 mg of this compound was put on a hotplate on low heat in my indoor greenhouse. The substance started to sublime. The little flies all around seem to panic and try to get away. After half an hour the flies seem to be uncoordinated and are for the first time even flying outside of the greenhouse.

Once I have determined the total yield after evaporating the DCM and bromobenzene off and after a quick boiling water wash I will check how the little buggers are doing and if necessary I will sublime a bit more of the compound.

source

Not many (big) plants yet, but I guess in July they will be competing for light.

[Edited on 6-2-2020 by Tsjerk]

Herr Haber - 6-2-2020 at 05:07

Wonderful !
Having Chloral hydrate and 100ml of Bromobenzene I was thinking about making this same DDT analogue.

You just saved me a bit of research for the workup

Tsjerk - 6-2-2020 at 05:23

Kein Problem!

One thing is for sure, this is one nice insecticide! Three hours in and no flies are flying anymore, only with the small sample run. Even better, the aphid are falling dead from the leaves by only giving the plant a little shake. Good stuff.

[Edited on 6-2-2020 by Tsjerk]

woelen - 6-2-2020 at 05:55

Aren't you afraid of potential health issues by exposing yourself to this stuff? It sounds like being quite toxic and you use this inside your apartment.

Tsjerk - 6-2-2020 at 09:51

DDT is not that toxic, not to animals other than insects at least. It gets toxic when it accumulates in fatty tissues, that was the problem in the 50's and the 60's and reason to ban DDT. The USA were producing 100.000.000 tonnes at some point... per month. And Europe was not far behind.

After some decades of usage at this scale, animals higher up in the food chain started to develop symptoms, like infertility and thin egg shells. Every time a mammal would breast feed offspring, the accumulated DDT would be transmitted, giving the offspring a worse head start in life than they had themselves. Birds would accumulate the DDT in egg yolk an pass it on that way.

Humans never got into trouble because from the beginning it was not aloud to spray the stuff a week or so before harvest. Also weeds used to feed life stock were not sprayed some time before harvest. DDT dissolves quite poorly and therefore is not taken up into plants, the dust does the job. When you sublime it, and are not present until the DDT settles on surfaces, and don't lick the walls afterwards, you won't get much into your system. The crops would get rid of the DDT either by rain or by washing the vegetables with some water before eating.

I'm not too worried about the probably ten grams I will need in a lifetime to eradicate every insect in my small greenhouses. Also the bromo-DDT is more bio-degradable compared to chloro-DDT. Fluoro-DDT is even more degradable, but on the milligram scale I'm using it... well, who cares.

When my grandpa learned about the upcoming ban on DDT he bought a 25 kg bag, that lasted about ten years, and he was running an indoor cattle farm with over a thousand calf. I never experienced the DDT time, but the days without were terrible, the shit-flies were everywhere, all day and all year. Apparently he could keep a whole industrial farm fly free with 2,5 kg a year.

I do remember a time at my uncles place... he had a special stash, just for inside use. When the flies would get to bad, he put a table spoon in a old can on the stove. We had to leave the house for an hour or so. After that... no flies for 6 months. Every fly landing on the wall would drop dead.

Edit: I don't even know the mechanism of action... I will have a look.

[Edited on 6-2-2020 by Tsjerk]

woelen - 6-2-2020 at 10:55

Interesting to see that a compound can have such a strong effect on insects, while being relatively non-toxic for higher life forms. I did not know that, I never dived deeper into the chemistry and selective toxicity of DDT. I indeed think that a few mg does not pose a serious risk for you. You also only get a tiny fraction of that in your system. a few tens of mg of release into the air is not equivalent to your body taking up that amount.

Fery - 6-2-2020 at 11:17

Tsjerk - wow, beautiful. I do not have any greenhouse, just garden. I attract ladybugs, they are very quick on eating the aphid. I observed that ants are spreading aphid larvae in my garden - aphid sucks plants so plants weep blood and ants sucks the blood then. When I see row of ants walking to any plant in my garden, they carry aphid and spread it to the plant, take care of the aphid and suck the blood of the plant.
Anyway nice synthesis !

DavidJR - 6-2-2020 at 12:02

Quote: Originally posted by woelen

That's nothing compared to modern neonicotinoid pesticides. Take for example imidacloprid. In mammals, it's not particularly toxic, with an oral LD50 of about 450mg/kg. To insects, on the other hand, it is incredibly toxic. This sounds like exactly what you want from an insecticide - but the unfortunate downside is that it (and other neonicotinoids) have had an extremely negative impact on non-target insects, most notably bees.

In that vial there is approximately 3.4g of pure imidacloprid. Imidacloprid is one of the most toxic-to-bees compounds known, with an LD50 of between 5 and 70ng per bee (some colonies are apparently more sensitive than others). Conservatively, I have enough in that vial to kill at least 24 million bees, and quite possibly enough to kill a few hundred million bees.

Neonicotinoids have also been strongly linked to colony collapse disorder in honeybees. Even at sublethal levels below the limit of detection, honeybees are adversely affected by them. They exhibit behavioural changes which lowers their rate of survival, and also, they become more susceptible to infestation by a parasite called Varroa mites.

In 2017, China alone exported 31,595 tonnes of imidacloprid. It's a wonder we have any bees left at all.

[Edited on 6-2-2020 by DavidJR]

Tsjerk - 6-2-2020 at 13:33

Quote: Originally posted by Fery

Tsjerk - wow, beautiful. I do not have any greenhouse, just garden. I attract ladybugs, they are very quick on eating the aphid. I observed that ants are spreading aphid larvae in my garden - aphid sucks plants so plants weep blood and ants sucks the blood then. When I see row of ants walking to any plant in my garden, they carry aphid and spread it to the plant, take care of the aphid and suck the blood of the plant.
Anyway nice synthesis !

Yes, ants and aphids have a lovely symbiosis, the ants protect the aphids as the aphids shit their (in Dutch) "honingdauw" all over your car. I understand the ants though, the aphid shit is pure sucrose.

Neonicotinoids are nice because they are biodegradable. I just had a quick look, apparently imidacloprid has a half life of 39 days, while DDT has a half life of 15 years. Also imidacloprid has been banned in the EU in 2013.

Without pesticides we would not have been here, with 7 billion people.

One the other hand , if DDT would have been banned 10 years later, or more accurately, if the ban would not have been forced on Africa, malaria would not exist today.

European countries used DDT to exterminate insects (and malaria) transmitting deadly deceases, and then found out orca's and ice-bears and some birds suffered, withholding Africans from using DDT, preventing them from eradicating malaria.

[Edited on 6-2-2020 by Tsjerk]

morganbw - 6-2-2020 at 16:50

Nice post.
I considered a DDT synth a very long time ago. I have yet to do so but I do still have an interest.

DavidJR - 6-2-2020 at 17:31

Quote: Originally posted by Tsjerk

Neonicotinoids are nice because they are biodegradable. I just had a quick look, apparently imidacloprid has a half life of 39 days, while DDT has a half life of 15 years. Also imidacloprid has been banned in the EU in 2013.

Without pesticides we would not have been here, with 7 billion people.

One the other hand , if DDT would have been banned 10 years later, or more accurately, if the ban would not have been forced on Africa, malaria would not exist today.

European countries used DDT to exterminate insects (and malaria) transmitting deadly deceases, and then found out orca's and ice-bears and some birds suffered, withholding Africans from using DDT, preventing them from eradicating malaria.

Of course - it is not quite so simple as just saying insecticide x is bad. Insecticides are certainly very important (but so are bees).

Tsjerk - 7-2-2020 at 01:38

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: still at least a 90% reduction of flies, only after the 50 mg test. As far as I can tell all aphids are dead. Normally they don't care too much when you touch them and the will stay where they are, now they just drop from the leaves with the slightest touch. I will know for sure whether they are dead or not in a few days, they turn brown after a couple of days when dead.

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.

[Edited on 7-2-2020 by Tsjerk]

[Edited on 7-2-2020 by Tsjerk]

Herr Haber - 7-2-2020 at 04:29

Keep sharing your thoughts Tsjerk

I have about 50 cardboard boxes in my living room after a major overhaul of the appartment but as soon as I'm done with that I'll proceed with that synthesis.

I wont need much either. I was planning on dissolving the bromo-DDT in a solvent so it could be painted on wood to ward off against hornets.
Dont really need them dead, just *away*.

mayko - 7-2-2020 at 06:57

First of all, nice chemistry; the di-bromo analog is an interesting twist. How did you manage waste disposal?

I’m not qualified to comment on the toxicology of DDT in any depth but things like the Pine River Statement (https://www.ncbi.nlm.nih.gov/pubmed/19750098) would make me …. reluctant to use it without very good cause.

Despite its reputation, DDT is not a magic bullet against malaria, for a number of reasons. A big one is insect resistance. Sri Lanka learned this the hard way in the early 1970’s, when their eradication program hit a brick wall: the insecticide they'd relied on just wasn’t working any more. In spite of intense spraying, they suffered a serious malaria outbreak, forcing them to switch IIRC to the more expensive malathion. Their eradication program continued without DDT, declaring success a few years ago.

The EPA has no jurisdiction outside of the US, so I’m not sure how it could have forced its ruling on Africa. Even if it could, the 1972 ban had a public health exemption (the later Stockholm Convention exempted DDT for the same reason). It also didn’t prohibit manufacture or export, which continued by the ton. According the the latest World Malaria Report from the WHO, several African nations are using DDT to this day. But while it remains a tool in the tool box, it has almost entirely been displaced by better alternatives. In particular, bed netting is more effective and less expensive than outdoor DDT spraying.

It can also be a false opposition to pit wildlife against disease control. Insectivorous bats and birds are our strongest allies in fighting mosquitoes, but are particularly hard-hit by DDT.

Tsjerk - 7-2-2020 at 08:08

There is a big difference between "a shown effect on fertility" and death.

When a species develops resistance, your toxin either isn't toxic enough or didn't use enough of it.

No, EPA (whatever it may be) does not have jurisdiction in any other country (?), but African countries usually don't have the facilities to produce DDT on a ton scale. When the USA and the EU decide they won't produce DDT anymore, the African countries are screwed.

Yes there are many countries, mostly African, that still use DDT, good for them. But they use it on a ton scale. Not a giga ton scale.

Edit: sorry, not a mega but a giga ton scale.

Edit 2:

Quote: Originally posted by mayko

How did you manage waste disposal?

I disposed everything down the drain. Do you think anyone down there would have a problem with that?

[Edited on 7-2-2020 by Tsjerk]

Johnny Windchimes - 7-2-2020 at 10:43

Where is NileRed's DDT video when you need it huh?

I used to have a copy but my hard drive bit the dust....

Anyone have a link?

Tsjerk - 8-2-2020 at 07:12

I just found out how to get the compound as a clean crystalline product. The stuff is remarkably insoluble in hot methanol, probably even less in cold methanol. I tried to recrystallize the DDT with methanol, but nothing seemed to dissolve, bromobenzene however is miscible with methanol. I was left with a pure white powder after filtration. No melting point was measured, but it is far above 100 degrees. That is good enough for me, as I used bromobenzene in excess and let the reaction go for about 24 hours.

Next time I will try to directly crash the DDT with methanol.

Quote: Originally posted by Johnny Windchimes

Where is NileRed's DDT video when you need it huh?

Need it for what?

[Edited on 8-2-2020 by Tsjerk]

mayko - 8-2-2020 at 07:30

Quote:

There is a big difference between "a shown effect on fertility" and death.

Sure, the chronic effects of pesticide exposure must be weighed against the acute risk of infectious disease – I don’t know how anyone could disagree with that. My point, though, is that there is a big difference between dying of malaria and having aphids on one’s houseplants.

Quote:

When a species develops resistance, your toxin either isn't toxic enough or didn't use enough of it.

I don’t know where to even begin with this. It’s tautological in not one but two dimensions. We measure toxicity in terms of LD50, because the LD100 just isn’t a useful figure. Even if it was, there is no reason to think that it would be practical or even feasible to administer an LD100 on a national or global scale. Agricultural use on crop pests (which is what almost all “bans” targeted) are another, uh, fly in the ointment. (A similar situation exists today with antibiotic resistance: it’s obviously important to follow a full course of antibiotic to prevent resistance, but that’s only going to help so much when Farmer Bob next door is pumping his pigs full of the same stuff as a preventative measure. Upping the amount used also increases the selection pressure for resistance. Finally, how resistance arose is not relevant: it’s here, it’s not going away, and it’s dramatically reduced the effectiveness of DDT.

Quote:

No, EPA (whatever it may be) does not have jurisdiction in any other country (?), but African countries usually don't have the facilities to produce DDT on a ton scale. When the USA and the EU decide they won't produce DDT anymore, the African countries are screwed.

The US continued to manufacture and export DDT for at least another decade and a half. The US and Europe are also not the only places in the world with chemical industries. China was a major producer until recently. India is the last big one and is in the process of phasing it out. The reason isn’t a 1972 US EPA ruling. DDT played an (important but often overstated) role in the US eradication program, but most of a century has passed since, and now it’s largely obsolete.

Tsjerk - 8-2-2020 at 08:12

Quote: Originally posted by mayko

I used 50 milligram.

[Edited on 8-2-2020 by Tsjerk]

XeonTheMGPony - 8-2-2020 at 11:41

Quote: Originally posted by woelen

Interesting to see that a compound can have such a strong effect on insects, while being relatively non-toxic for higher life forms. I did not know that, I never dived deeper into the chemistry and selective toxicity of DDT. I indeed think that a few mg does not pose a serious risk for you. You also only get a tiny fraction of that in your system. a few tens of mg of release into the air is not equivalent to your body taking up that amount.

Most bug sprays are nerve gas for bugs, where most animals can metabolize the substances

Permethrin is extremely lethal to ticks and fleas, but harmless to humans and dogs, but interestingly, all so very toxic to cats!

https://en.wikipedia.org/wiki/Permethrin

Why some tick and flea treatments can not be used with cats.

DavidJR - 8-2-2020 at 11:50

I never found permethrin to work all that well on fleas. Also, it is found in flea collars etc intended for cats...

Frontline, active ingredient fipronil, used to work pretty well, but in some areas there are now fipronil resistant fleas. We had to switch to Bayer Advantage, which is imidacloprid (dissolved in benzyl alcohol which leaves your cat smelling of almonds for a few days). This works very well indeed.

XeonTheMGPony - 8-2-2020 at 13:11

Quote: Originally posted by DavidJR

I never found permethrin to work all that well on fleas. Also, it is found in flea collars etc intended for cats...

Frontline, active ingredient fipronil, used to work pretty well, but in some areas there are now fipronil resistant fleas. We had to switch to Bayer Advantage, which is imidacloprid (dissolved in benzyl alcohol which leaves your cat smelling of almonds for a few days). This works very well indeed.

there is a natural form and synthetic, the synthetic is the most lethal to insects (And cats), I use it mainly for ticks and it is a non miracle for that! ticks are horrible in my area, and I have gotten it down from hundreds a day on the dogs and me to a dozen a day during tick season, I spray the house the bed, the dogs bed the clothing.

I looked up the synthetic route at some point but can't recall.

Tsjerk - 8-2-2020 at 14:45

I got a dry crystalline substance after a methanol wash. The yield sucks, I don't know what it is but I guess about 20 grams. That should be a lifetime supply though. I just subblimed 100 mg in my greenhouse. Just to be sure.

I will report anything flying or crawling around in the next months.

unionised - 9-2-2020 at 10:17

Quote: Originally posted by XeonTheMGPony

there is a natural form and synthetic,

There are natural pyrethroids but I doubt permethrin (with two chlorines in the structure) is natural.

Herr Haber - 10-2-2020 at 04:09

Quote: Originally posted by unionised

Quote: Originally posted by XeonTheMGPony

there is a natural form and synthetic,

There are natural pyrethroids but I doubt permethrin (with two chlorines in the structure) is natural.

Indeed.
Permethrin WILL kill a cat.
Many cat owners killed their pet by using those droppers / syringes made for dogs.
Many insecticides in your average hardware store arsenal contain permethrin as I discovered a few years ago when I got scabies.

XeonTheMGPony - 10-2-2020 at 16:37

Quote: Originally posted by unionised

Quote: Originally posted by XeonTheMGPony

there is a natural form and synthetic,

There are natural pyrethroids but I doubt permethrin (with two chlorines in the structure) is natural.

exactly natural form with the y Pyrethrin, artificial with the e

y one is safe with cats, the synthetic how ever works the best.

Dr.Bob - 10-2-2020 at 20:07

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.

Tsjerk - 10-7-2020 at 03:46

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.

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.

Tsjerk - 25-7-2020 at 03:44

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.

Tsjerk - 9-12-2020 at 07:28

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.

aromaticfanatic - 9-12-2020 at 19:55

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.

Tsjerk - 10-12-2020 at 02:43

I bought it from Mario.

morganbw - 10-12-2020 at 19:37

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]

Tsjerk - 10-8-2021 at 13:29

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.

Tsjerk - 13-12-2021 at 13:44

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.

karlos³ - 13-12-2021 at 14:23

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!

Tsjerk - 13-12-2021 at 23:21

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.

karlos³ - 14-12-2021 at 06:36

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.

Tsjerk - 14-12-2021 at 11:01

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

Tsjerk - 21-3-2022 at 13:35

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 20-25^oC 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]

Tsjerk - 27-4-2022 at 02:42

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]

Fantasma4500 - 27-4-2022 at 06:27

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

Tsjerk - 27-4-2022 at 08:16

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.

Tsjerk - 28-6-2022 at 02:26

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]

Bromo-DDT using Chlorosulfonic acid

Tellurium - 27-8-2022 at 10:22

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 257 times

Tsjerk - 27-8-2022 at 14:10

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.

Tsjerk - 28-8-2022 at 11:17

I saw the same red color when I used P2O5 btw.

Texium - 29-8-2022 at 08:04

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!

Tsjerk - 2-9-2022 at 10:07

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]