PLEASE HELP! Water bath and rotovap questions…

[Rabidreject]

Hey guys,
I have a synth coming up (currently waiting for the main reagent) and the synth calls for both a water bath and rotovap.
So to put my situation into perspective it’s important to say that I am learning chemistry as a hobby and I do not make things for people other than myself!
Okay so firstly with the water bath, is it to remove solvents or to keep the rxn going at a very specific temp? Or both? Or neither?
Secondly, it says to put the RM into a rotovap and strip it of the solvent - now, being a hobbyist chemist, I obviously do not have a rotovap - and it would take A LOT for me to obtain one.
I can understand why it would be incredibly useful, however, I was curious if I can just strip it of solvent under vacuum so as not to harm the valuable, yet relatively fragile compound I just created.
I understand it’s not a set and forget way of doing it, it’s just annoying that I’ll have to keep an eye on it.
Can someone take the time to explain? I’m sorry if these are really basic questions and no one takes me seriously, given how I am learning on my own and am operating on a VERY limited budget!
Oh also, can someone recommend a fairly decent rotary vein vacuum pump that is worth buying to run reactions? I’m in the UK but the way we all buy everything from China anyway kind of means suggestions can be made. I bought one before, however, didn’t realise it was a silly non oil one and can’t be left on for long and so it’s being used as my pump for filtration instead of being used for RXN’s.
I know I am asking a lot with this post but really any help would be GREATLY appreciated!
Regards
RR

 

[OTC_HomeChemist]

Hey,

The water bath is just used as a means of heating your glassware evenly and to a certain temperature. There are certainly other ways to do this but a water bath can be easily created by simply putting a pot or heat resistant glassware on a hot plate.

A rotavap is just a convenient way of removing solvents from a reaction mixture but never necessary and a vacuum distillation setup is an even better option in many ways. Magnetic stirring or boiling chips will improve the process and might even be absolutely necessary depending on what you want to distill.

There are cheap and rather silent vacuum pumps without oil that can run for long periods of time but they will not create a very strong vacuum.

Vacuum pumps for really Low pressure are either rather expensive or very fucking loud.

If you have a water tap with good pressure then a Venturi Vacuum Adapter might be a good choice and has many advantages and the vacuum will be strong enough for most needs.

Depending on the compound you are trying to distill a Steam distillation might be another good option. Even though it's rather slow it might lead to a much purer product depending on various factors.

 

[Rabidreject]

Interesting and thanks so much for the response. I’d basically what I thought yeah - unfortunately I need the pump in order to the distillation as I have to be of the non oil ones that can only run for a slow amount of time.
yeah I considered an aspirator but wasn’t sure how much it would bring down the boiling point - trouble is I either have a water pump to use it with OR a kitchen sink tap that it wouldn’t connect to….
Noise, I don’t really mind tbh, I’ll just use the method of quietening down grow fans for the pump if anyone moans - honestly my neighbours are used to me running electric saws and shit pretty frequently! I’m a bit of a loon with a LOT of hobbies!!
Am I allowed to say what I am trying to make on here? I didn’t want to put it in the title because there , honestly, are a lot of compounds I intend on making but I can tell you my precursor is tryptamine.
Not sure if a vacuum distillation is necessary but I know it would be preferably to non vacuum when talking tryptamines…..

 

[OTC_HomeChemist]

You can run an aspirator with a water pump as long as it has enough pressure and you should use a large water reservoir and/or change the water from time to time... Or chill it. Since the max vacuum pressure will depend on the temperature of the water. You can also always get an adapter for your tap. As long as the water pressure is ok then the vacuum will be strong enough for pretty much any distillation.

I've got an 800 Euro professional lab vacuum Pump and to be honest I hardly ever use it because it is so ridiculously loud. I've put it into a DIY Silent Box and used Rubber rings to hang it up and still .. I do use a Prima Klima exhaust fan for my fume Hood and it's pretty much running 24/7 and that does not bother me at all...

Water aspirator also has the advantage of no gasses escaping like Low boiling solvents, no need for a cold trap.

I'm pretty Sure that pretty much any substance is allowed on here so don't worry

 

[Rabidreject]

Oh okay that’s cool then. In that case I even have additional questions for you.
firstly, thanks for opening my eyes to the fact the temp of the water as well as the flow effects the vacuum an aspirator pulls - that’s really interesting.
honestly, I always end up adding ice to my pump pot as it’s such a small volume of water I run it in - I tend to just have either ice or at least, ice jars (what iv come to call jars full of water, put in the freezer) oh and I add salt to the water.
okay so I’m trying to make DMT - among other primary amines - now, I KNOW a vacuum isn’t NEEDED but I do have one question regarding the synth for DMT.
I’m lookin to follow the ‘hamilton’s guy with the three eyes route’ which calls for making STAB in situ.
I understand all of that rxn and great, exothermic and also needs to be kept in an ace bath anyway so perfect for my needs.
what I’m wondering is, at the end of the YouTube video if you search for DMT synthesis and look at his guys process he says right at the end - he then uses PH to manipulate it in an anagolous way to if you were doing MHRB.
Now, does that mean I use sodium hydroxide seeing as the stab you make in Situ is acidic?
Also I only have 3a mol seives but as I understand it, someone else on here said 3a work better.
I also intend to make DET (I’m actually more interested in things OTHER than DMT that I can make from tryptamine) and have some alcohal/ acetaldehyde coming (but a really small amount!). Search Reddit for DET SYNTH and yet again Hamilton has made a post where you basically substitute the formaldehyde for acetaldehyde and you get DET? Is this correct? Pretty sure he says to only use NaBH4 on that one though….

 

[Rabidreject]

Man, sometimes I just feel iv taken on too much and then i just think of all iv learnt in about 5 or 6 months and think maybe it is worth sticking with as a hobby.
it’s being able to affford 1kg minimum orders from China that’s my main issue!
I’m lucky I got someone to sell me 500g of tryp from HK for a decent price compared to half a key of either 3,4,5-tmoba or 2,5-dmba to make interesting phenethylamines but then you need the nitro too…
Gosh it’s all very long,,.,YET ADDICTIVE AS F.
I’m literally trying to quit drugs and yet chemistry is helping me do it which is kind of counterintuitive!

 

[Rabidreject]

I do appreciate that those pumps could be loud AS FUCK tho! I live in a flat too!! Maybe aspirator is the way to go. Do they make any maybe rubber converters or something that wrap around a sink type tap as opposed to one that was like what we had in the chemistry lab at school…you know the ones that look like the intake of any gas or water inlet on glassware?

 

[Rabidreject]

I assume a more powerful water pump = higher pressure also, if I’m icing my water? I can always find a bigger tub to hold said water too which means more water and less heat

 

[Rabidreject]

Dang, why did I buy a cold trap so early on?! Haha I guess I can use it with my non oil pump for 20 mins at a time! Haha jk

 

[Rabidreject]

Oh also can you clear something up for me because I’m a little confused over negative pressure gauges.
I watched pootube video and it said a lower number = a higher rate of vacuum but IME a higher number (because it’s in negative) = a higher vacuum))

 

[Rabidreject]

Fuck….im realising im going to need more DCE and my italian provider closed down (even though im in the UK)

 

[Rabidreject]

Oh shit yeh that’s wot I was going to ask. How do you know what pressure your pulling on an aspirator?