atmospheric isomerization

[SuperStar]

Question. SWIM is getting ready for the isomerization of safrole. SWIM keeps reading all this different post by Kapten and VL about all of these elaborate setups, turning vac on, turning vac off, etc, bla bla bla. Then abacus is saying just at 10% KOH heat to 125C, stir for 12 - 14 hours and distill iso.  It seems that even Rhodium agrees with this method. So what is all this talk about all these different setups? Are these just to save time?  Or are yields considerably lower with just 125C and stirring?

The abacus way just seems to simple to not go this route. Setup, stir, go to bed, distill.

What am I missing?
Pardon my friend officer, He's a little slow.

[pickler]

It's more of a personal preference. Swim has tried VL method(which Swim likes) and the stirring method. Guess time is the factor to swim.
We'll soon find out if I'm a chemist or not!

[dr_ruthenium]

However, if you don't know that your sassy is 90%, then you might have eugenol.  Eugenol evaps at 252 C, just like trans-iso.
Seratonin is a succulent fruit to be plucked from your axonal terminal boutons sparingly.  Dr. Ru

[abacus]

Well said kapten, no doubt your dog tried it and it is as simple as it seems.  No tar, high yield, no vacuum to bother with, So easy.

The only extra thing that SWIM does after stirring for say, overnight, is to add a full vacuum and gradually raise the temperature until it bubbles in the flask (without distilling over).  If the observed bp is a bit lower than the trans iso should be (and closer to the bp of safrole under the same conditions), SWIM keeps stirring (under vacuum) until the bp goes up to that of the trans iso.  You can nudge it up over 30 minutes quite well. 

This ensures full isomerisation and full yield.  Then crank up the heat and vacuum distill.

Abacus.

[SuperStar]

Abacus, Help:

SWIM has just done an isomerization.  Took 480g of distilled safrole. Added 48g KOH flakes.  This was added to 2L beaker. This was placed directly on digital hotplate. The temp of the solution was brought to approx 125-130C.  The stirrer was turned on mad. The solution went thru a few different color shades but mostly stayed at dark black/brown.  The problem, I think, is that the solution was sort of steaming all night long.  I don't understand what all of these steam would have been. Certainly there was not this much water?  SWIM started with 600ml of safrole + KOH flakes. SWIM now has approx 300ml of dark brown solution with KOH flakes.  What happened to the 300ml of something?  There was no boiling, just light continuous steaming.

SWIM thinks this should have been done in a 1000ml flask.
Pardon my friend officer, He's a little slow.

[Osmium]

OMG!

Congratulations, you evaporated away half of your safrole/isosafrole. Bet the smell in your house was really nice!

What happens when you put a pot of water on a hot plate without lid and leave it alone overnight? Some of the water will evaporate. Now what makes you think that safrole will NOT evaporate at elevated temperatures?
Use some common sense!
I'm not fat just horizontally disproportionate.

[SuperStar]

Thanks Osmium,

Must remember SWIM is very new.  Thought the idea was to drive out the water from the Isomerization. SWIM really didn't have any idea that safrole would evaporate at temps of 125-130C since the bp is 232C. Well fuck!  So what is the correct physical setup for this atmo stirring isomerization. SWIM assume should have been loaded in a fract dist setup?  If loaded into setup like this how to get the water out, or is this not a problem?
Pardon my friend officer, He's a little slow.

[SuperStar]

So now SWIM has approx 300ml of black/brown shit with lots of KOH flakes. What to do now?  Filter the solution to remove the flakes?  Or just go ahead and vac dist iso?
Pardon my friend officer, He's a little slow.

[SuperStar]

Kapten:

I think at one poing in time all of the flakes may have been disolved. Not completely sure about this. Since so much safrol has evaporated he would find it hard for all the flakes he added to be disolved in this small amount of solution.  SWIM is back to his original question. What now?  What is the correct setup exactly? 

Abacus: Do you have your dist setup compeletly setup when you do this? Do you have a fractionaiting column in place? Or do you have a condensor with water? no water?  Is the mixuture refluxing? Any condensation? 

SWIM has read so much and been so careful but must agree with Kapten, don't think this part was clear enough for newbees.

Pardon my friend officer, He's a little slow.

[SuperStar]

Kapten: That make SWIM think that abacus has his entire dist setup. So then he stirs all night and then applys the vac in the morning, then slowly adds heat until is gets close to the trans temp and away from the safrole temp.

The big question here is he using a reflux condersor with water, a fractionating colum, or what?
Pardon my friend officer, He's a little slow.

[SuperStar]

Abacus: Get home and answer SWIM's question!  SWIM is depressed over his mistake, needs help fast to redeem.  Luckily SWIM still has mo safrole.
Pardon my friend officer, He's a little slow.

[SuperStar]

Somebody page abacus. SWIM is dying over here. 
Pardon my friend officer, He's a little slow.

[cheeseboy]

1:As for the question about evapping safrole, YES safrole/sassafras oils are what's known as "volatile oils". That means they evapourate very quickly at room temp.
  2: You shouldn't be doing these runs without a distillation set up.
  3: Cheese never tried this but in a 100g safrole run, you can add your 1g of KOH PLUS 15g of CaO (lime) and reflux at 242°C for 15 minutes with 90% yields!
  4: Cheese tried adding the KOH without any alcohol, then heated it to a boil (100 C) and collected/discarded all the H2O that comes out of the KOH. Once there is no more water coming off, change your condensor to vertically lie on top of your flask and reflux at temp between 120°C-140°C for 4 to 5 hours. Change back to horizontal condensor and bring temp up to 252°C to collect Isosafrole at 80% yields (roughly).
  5: Answering your Oxone question:  You are right, you just mix everything together (dH2O, Oxone, methanol) and filter out the salts created by the MeOH being added, THEN add your Isosafrole and spin (in a beaker is fine for THIS..LOL) Or a garbage can for huge runs!LOL   This filtering of the soot before the isosafrole's added makes things very easy after the Epoxide is formed, as you can load the whole shebang into your sep funnel AFTER decanting most of the Aqueous solution off first, then tap off the Epoxide -or Glycol if you did NOT add bicarb as a buffer. I hope this helps SuperStar. You're doing just fine, and remember, there's no such thing as a dumb question, and making mistakes are THEE best way to learn!! cheerse
May De Sorce Bee Wit Chu-Always

[SuperStar]

I agree with Kapten here. SWIM would try but since the earlier fuck up running a little low on go go juice.  Sounds like it should work though. SWIM would suppose you would need a flat bottom flask to put directly on the hotplate?

BY THE WAY:
SWIM has once again started the abacus isomerization. This time using 400g distilled safrole, 5%(20g KOH), 1L RB Flask, reflux condensor with running water on top, heating oil bath to 155C, equals 130C on the goodies.  This makes complete since now that SWIM is doing it.  Can't believe fucked up 400ml of good stuff earlier.  Another big set back like that and SWIM could be out of commission.
Pardon my friend officer, He's a little slow.

[pickler]

here's the synth. It's on Rhodium's page.

Isomerization with KOH/CaO[9]
If calcium oxide is added to a mixture of potassium hydroxide and safrole, the reaction becomes less water-sensitive as the CaO reacts with any water present to form Ca(OH)2. The reaction is also very fast. The downside is that the CaO forms a black insoluble gunk in the reaction flask, and has to be removed by vacuum filtration with a filter aid before the isosafrole can be distilled off.

Experimental:

100 grams of safrole was placed in a 250 ml RB flask fitted with a water-cooled Allihn reflux condenser, and was heated with good stirring. When the solution started to boil, 1 gram of KOH pellets was added through the condenser, and the safrole immediately took on a brown color. Next, 15 grams of CaO was also added through the condenser, and the solution was allowed to reflux for 15 minutes, and the heat was turned off, and the solution was poured into a beaker and was allowed to cool. The dark brown suspension was vacuum filtered through a pad of celite, and the filter cake was washed with 2x50 ml of CH2Cl2. The CH2Cl2 was removed through distillation at atmospherical pressure, and unreacted safrole was also distilled off at 240°C (bath temperature), and amounted to about 1 ml. The residue was distilled at aspirator vacuum (~25 mmHg), and the isosafrole came over at 120-130°C as a water-white oil, weighing 70 grams (70%).
We'll soon find out if I'm a chemist or not!

[head]

Thanks horn!
"Taking risks are part of laboratory science."
      - the Green Goblin

[Osmium]

Have fun filtering all that CaO. Good luck!
I'm not fat just horizontally disproportionate.

[abacus]

I have already explained this.  It really is very easy,just read what i have already said.  

1.  Setup for standard vacuum distillation.  Standard setup with RB flasks in normal distillation setup with vacuum hose attached to the vacuum receiver. 

2.  Add the KOH and heat up to say 120-150, really doesn't matter.  150DegC is good as you don't need to stir for very long.

3.  If you want, add vacuum for a few minutes to drive any water out.

4.  Release vacuum and continue to stir with heat, disconnect hose from vacuum source.  Go to bed or whatever

So the point is the glassware is STILL set up for vacuum distillation.  Removing the hose from the vacuum source is all you need to do.  The safrole won't evaporate and no smell is released.

5.  Next day, add vacuum and get it so that the iso is bubbling in the flask, but not boiling over.  

This is the only tricky part, if your heat is too high and your vacuum too much, you can get an instant distillation which is NOT what you want.  Thats why i do it at a temperature between the bp of safrole and iso under full vacuum. That is, I add full vacuum at said temperature and if the reaction is complete, I get no bubbling and conclude the reaction IS complete.  However, if i get some bubbling, i keep stirring until it goes away.

Practice will soon learn you your best conditions.

If you are satisfied that the bp is that of trans iso, and higher than safrole you are done.  As said, it is easy to get bubbling but not distilling, let stir until bubbles subside, increase heat etc.

Normally takes about 30 minutes until you see the bp is way higher than the starting safrole under the SAME vacuum.

6. Crank up heat some more and vacuum distill your iso.  No safrole forerun if you do what I said.  90-95% yield

7.  Wash your flask with water.  No crap to get rid of.

8.  So I repeat, setup glassware for distilling, DONT just heat in a beaker with KOH, my posts never said that. 

I cant explain this much better, hope this helps

Abacus.

[SuperStar]

Thanks abacus,

Just so no one makes the same mistake again. When you said stir and heat to 125C and everyone on the board is talking about all of these water problems. SWIMS assumed that the reason for the 125C was to get it just hot enough to evap the H20. Hince the open beaker to let the water get out more easily.  Now SWIM is starting to understand that the water is not a problem for everyone. SWIM has it setup for reflux right now and has been refluxing and stirring all night. Next time I will setup the complete setup, reflux setup alone still lets some odors into the room, nothing bad though.
Pardon my friend officer, He's a little slow.

[SuperStar]

Just in case everyone is wondering SWIM is a little excessive compulsive.

One more question:

Do you use a fractionating column when you distill Iso? Is fractionating column necessary.  SWIM has a short vigreux but did not use it for safrole distillation.
Pardon my friend officer, He's a little slow.

[Osmium]

> When you said stir and heat to 125C and everyone on the
> board is talking about all of these water problems.

There are no water problems. Don't make this more complicated than it really is.

> Is fractionating column necessary.  SWIM has a short
> vigreux but did not use it for safrole distillation.

It is not necessary to use one, but if you have one lying around, and if your vac is good enough so you won't lose too much it is ALWAYS advisable to use one.

I'm not fat just horizontally disproportionate.

[SuperStar]

Thanks Osmium:

SWIM definetly needs a little pep talk, starting to get overwhelmed.

Update: Been stirring all night with reflux condensor.  Now ready to vac distill.  Oil bath has cooled to 50C.  Hooked up vac and turned on vac as low as possible. SWIM is getting a bunch of suds forming and climging the flask and still head.  Turn off vac and go away but as soon as vac is applied they start forming and climbing.  SWIM is letting oil bath continue to cool right now and try again.  Anyone seen this and have suggestion. If SWIM keeps vac on the suds will definetly climb all the way over.  BTW: SWIM's vac distills safrole at 100C, sort of strong, but can be turned down to what SWIM would believe sass comes over at 140C. The vac is on the lowest setting right now but still forming suds.
Pardon my friend officer, He's a little slow.

[greeter]

4.  Release vacuum and continue to stir with heat, disconnect hose from vacuum source.  Go to bed or whatever

What temp do you stir it at overnight, the same temp as that used to drive off the water, or ?

[Chromic]

>Is fractionating column necessary.

They are not necessary but if you do not have one get one now! They are especially useful for distilling ketone. Again, it can't be said enough, GIGO. If you're not carefully separating your safrole, iso and mdp2p... you will get really terrible yields. (take my word for it)

[SuperStar]

Thanks noj and Chromic,

SWIM is having a terrible time with this.  SWIM distilled safrol twice.  Once it came over at 90C, the next time around 100-103C.  Right now SWIM has something clear coming over at 90C. SWIM dosen't know what it is?  Vac is too strong for it to be water.  It can only be two things, safrole or isosafrole.

Right now SWIM is planning on distilling everything he has. The messed up stuff from yesterday and the shit that is coming over right now at 90C.  Then combining everything together and starting over with the iso. 
Pardon my friend officer, He's a little slow.

[abacus]

A couple of other points. 

1.  10% KOH is too much and a waste.  3% works fine.

2.  Greeter, my answer to your question is: My vacuum pulls safrole over at 115-120DegC, so i heat up to say 110 under full vacuum which makes sure any water present is boiled away, then release vacuum and heat at 140DegC  or so, and go to bed. 

Water has never been a problem.

It really is very simple and its a matter of choice how you like to do it.  I like doing it the way i explained beacause i only have to set up my glassware once.

Abacus

[LaBTop]

See

Post 294437

(LaBTop: "Prefered next steps after freezing:", Methods Discourse), I have just editted it extensively so even the most fresh beginner will hopefully understand it.
It explains why and how things should be done after sassafras to safrole, freezing out and distilling proceedings.
For those proceedings, read the whole damm important thread, did we type all that stuff for nothing?
Especially read the last line in that

Post 294437

(LaBTop: "Prefered next steps after freezing:", Methods Discourse).

Follow proceedings outlined by me in that whole thread, and you will have no problems with your ketone, obtained through the next procedure after isosafrole: a performic or peracetic procedure. LT/
WISDOMwillWIN

[pickler]

When you apply your vac to your oil, it will foam. If it's hot, it foams more. Just vary the vacuum. Start on the lowest setting and slowly increase the vacuum. If it gets out of control, then back the vac off a little. Takes a little bit to get the hang of. Or you could just let your oil cool completely down and go from there. It happens to swim all the time. Nothing to worry about. If you think it's bad with your vac you should try swim's vac. Pulls safrole at 70-72c. If your unsure what is coming over then just distill without vacuum. It's much easier for seperation of safrole and isosafrole.
We'll soon find out if I'm a chemist or not!

[SuperStar]

Thanks Pickler,

SWIM is starting to get it back together again.  Glad to hear about your vac. SWIM thought he bought way too big of a pump. Right now SWIM appears to be pulling ISO at a steady 91C. The thermom has not moved in about 2 hours.  SWIM is starting to think that the suds could be from too much KOH. 1st time used 10% by weight. Don't know who said this but that is way too much, SWIM thinks somebody said use 10% if you are using undistilled safrole(oil).  2nd time tried 5% by weight.  Next time going to adjust the numbers to 2% by weight.

SWIM is thinking that so much vacuum might make distilling not as pure as doing it at higher temps? SWIM's hotplate cannot get the oil bath above 175C, so everything must come under that.
Pardon my friend officer, He's a little slow.

[LaBTop]

Make that ~30°C under that 175°C of your oilbath.
The 30°C extra are "used up" in providing enough energy to let your isosafrole vapours reach the stillhead and the mouth of the watercooled condenser, where it can be condensed and start flowing to your receiver flask.
You need quite an overshoot in temperature to push concentrated boiled off vapour all the way up.
On their way up, inevidently part of the vapours will be so much cooled off by the vigreux column, that they condense on the spikes and walls of the vigreux and fall back as drops in the flask again.

The whole trick with the vigreux is simply said to play around with your temperature setting in such a way, that the first fraction, the safrole residue, which needs less energy to reach the top than the isosafrole, will come over, and the isosafrole will all the time condense and fall back while that is happening.
Your vacuum must be the same setting all the time, or your vigreux column can not do it's trick.
You only gradually increase the temperature under the same vacuum, to reach the point where the safrole starts condensing in the condenser, but the isosafrole keeps falling back from the vigreux.

Then, after no more safrole will come over at that lower temperature, you discard the contents of the receiver flask, and increase after that the heat again, and then all your isosafrole will come over at a higher temperature setting.

Did everybody forget already to put a 3-way valve between the condenser and the vacuum alonge, so you can maintain vacuum in the system while removing receiver flasks?
That way you won't have that famous foaming, caused by re-introduced AIR when you apply full vacuum on the whole system again, without a 3-way valve. And avoid oxidation/carbonization of hot oils. LT/

WISDOMwillWIN

[abacus]

Superstar, you need a better hotplate, and make sure you wrap everything in foil to minimise heat losses.

So your next question you will ask is; what will I do if i have distilled a mixture of safrole and isosafrole or you think you have.

Take your distilled mixture, add some fresh (say1% KOH or less) and heat.  If the solution stays virtually clear and your KOH flakes don't really dissolve, you have no safrole in your flask and you have iso, if it goes brown you still have unconverted safrole so keep refluxing or stirring.
 
Of course then you have to distill out the iso again but it's better than wasting all that unreacted safrole on the next steps.


Over And Out

[cheeseboy]

You can magnetically stir through a soft style heating manlte and control the temp with a variac controller. That sounds just as good or better than the hotplate/stirrer combo.
May De Sorce Bee Wit Chu-Always

[chem_123]

in having this sass. oil:

pinene..........    2-10%    Bp= 154C at 1 atm
phellandrene.    2-10%    Bp= 175C at 1 atm
d-camphor....    0- 5%    Bp= 204C at 1 atm
safrole..........   80-90%    Bp= 234C at 1 atm
eugenol........    0-10%    Bp= 252C at 1 atm

as stated in

Post 294437

(LaBTop: "Prefered next steps after freezing:", Methods Discourse)
SWIM was wondering bp's are the best way to get rid of anything but safrole (except eugenol)?

SWIM's read that using a naoh solution is good to get rid of the eugenol?

if that's true, would a bee just do the naoh wash on the sass. oil before distilling (or freezing), then take time doing a distillation in order to carefully watch the temp, and then the bee will know when the safrole is coming over?

SWIM's got the brown safrole/koh mix refluxing, and was wondering...how much time is necessary for conversion? (SWIM's read overnight...but the aspirator is gonna eat up some serious water(will running it overnight make a big difference on the water bill?), so a more accurate estimate would bee nice!   )
Dreaming of the sweet honey  

[chem_123]

SWIM's noticed that within the 4 hour time span of reflux with a 300mm vig. and a tap cooled condenser, that the drops coming from the condenser to the column off of the drip tip started clear, then went to a milky color, then back to clear...is this a good indicator that the reflux is done?
Dreaming of the sweet honey  

[Rhodium]

Just distill, there isn't any eugenol to speak of in sassafras oil, according to investigations by Osmium.

[chem_123]

what about the others?:


pinene..........    2-10%    Bp= 154C at 1 atm
phellandrene.    2-10%    Bp= 175C at 1 atm
d-camphor....    0- 5%    Bp= 204C at 1 atm
safrole..........   80-90%    Bp= 234C at 1 atm
eugenol........    0-10%    Bp= 252C at 1 atm

distill and discard first bit?

Dreaming of the sweet honey  

[Rhodium]

Exactly. The low-boiling components is of no use to us.

[GOD]

Swims sassy is brown, and after distillation, there is a very small amount of sediment and brown residue that obviously has a bp higher than safrole.  The oil is ~85% safrole, and takes about 3-4 cycles of freezing/thawing (at~8C) in order to remove all of the brown colored impurity, further freezing doesnt seem to clean it any further, and there still remains a little (teeny tiny bit) of cloudyness.
  Swim has performed three isomerizations that have for the most part failed (very minimal yeilds of iso).  He ASSUMES that this may have been because he couldnt find KOH anywhere in his vicinity including (finally) the chem supply which would only order a big assed drum.  The only thing he had was pH raise (solution) from the hydroponics store, he boiled it to dryness (actually scorched it) then baked in the oven.  When added to the sass, it turned dark (brown-red-almost blackish).  He applied vac for a good hour, his pump must have sucked up any moisture 'cause nothing condensed.  He tried one run with vac overnight, one run atm.  Two oxone runs yeilded very little product, and the temp for both of em never got much past 30C.
  Swim finally (after much planning and scheeming) aquired some KOH PELLETS (which hes going to lightly grind and filter w/bug screen) and is gonna give abacus' method a whirl.  The reason swim says this- is now he wonders if eugenol is present (hes got that funny sass dontcha know!)will that fuck up the isomerization as well? -so swim knows whether or not he should just go ahead and distill that sass anyway.
BTW, speaking of freezing out sass-
swim has managed to separate safrole/iso out of dirty ketone post oxone+hydrolysis . It was distilled, but for some reason, even with a vigreaux (granted it was jacketed with foam insulation, swim will switch to fleece material) everythin came over between 86 and 96C!  He has also managed to separate a bunch of safrole from his unreacted iso/safrole mix- although he has yet to confirm by atm bp (hes still in the process)- he has been alternating freezer (freezes both iso and safrole, fridge ~10C separate unfrozen supposive iso, thaw frozen safrole, reseed in fridge, separate etc....will post a new thread if successful (will check by doing both atm bp, then distilling to see if 2 fractions come over).
  As far as vac distilling goes, swims been using a ritchie yellowjacket, oil changed after every use -plus, swim finally got good silicone greece and used clamps on the vac hoses as well as using ptfe tape on vac nipples and thermo adapter- swims gotta do something about that vac, its too damned strong - even with gas ballast full open).  The adapter that fits to swims pump, its a 2-way adapter- will it harm the pump if he slightly unscrews the cap on the unused nipple?  Swim is at a loss, and doesnt have the $ to invest in a weaker pump at the moment.  Any other ideas- that wont end up doing damage to the pump?

[Osmium]

> When added to the sass, it turned dark (brown-red-almost blackish).

That's normal.
Why do people always assume that chemical reactions yield clean, colourless products? They ususally don't, not without some serious effort of cleaning up the products, especially not when using aggressive, highly corrosive reagents, employing natural precursors, are prone to side reactions and conducted at an elevated temperature!
More often than not you end up with an ugly horrible chunk of tar that has to be cleaned up extensively until it starts resembling anything remotely pure.

> Swim finally aquired some KOH PELLETS (which hes going to
> lightly grind and filter w/bug screen)

If you finally want to see some success you better leave them alone! Do NOT grind them and do not manipulate them unnecessarily. Just dump them pellets into the sassy and go ahead, as I told bees to do in the original writeup.

> The reason swim says this- is now he wonders if eugenol
> is present (hes got that funny sass dontcha know!)will
> that fuck up the isomerization as well?

I've personally analyzed several samples of sassy and never found any eugenol. And even if there were some traces present it won't matter.

> ...he should just go ahead and distill that sass anyway

Can't hurt, but assuming you only have an oil pump available you might just as well skip it.

> swim has managed to separate safrole/iso out of dirty
> ketone post oxone+hydrolysis . It was distilled, but for
> some reason, even with a vigreaux everythin came over
> between 86 and 96C!

I wouldn't expect any different! 3 compounds (safrole, cis and trans iso) with fairly close boiling points, distilled with a strong pump means shitty separation.

> swims been using a ritchie yellowjacket, oil changed
> after every use

That's unnecessary. I've used the same oil in pumps without cooling trap for well over a year.

> swims gotta do something about that vac, its too damned
> strong - even with gas ballast full open).  The adapter
> that fits to swims pump, its a 2-way adapter- will it
> harm the pump if he slightly unscrews the cap on the
> unused nipple? 

No, but it will start spewing oil mists out of the exhaust. Connect a cheap clear PVC hose to the exhaust, the oil will condense inside and flow back into the pump.
Other ways to admit air into your distillation:
* a capillary bubbling into your distillation flask (won't need any stirring anymore)
* sticking hypodermic needles into the vac tubing
* using a finely adjustable needle valve

> Swim is at a loss, and doesnt have the $ to invest in a
> weaker pump at the moment.  Any other ideas- that wont
> end up doing damage to the pump?

An aspirator!
When you do the vacuum isomerisation you don't have to suck a vacuum throughout the reflux. Just switch off the pump, or disconnect it after a while with a valve on top of your condenser. If your apparatus is fairly gas tight it will hold the vacuum for many hours. Try to adjust the vacuum so that the internal flask temp is somewhere around 120-130°C or so, that temp range worked well for me.
I'm not fat just horizontally disproportionate.

[RoundBottom]

SWIM has never had a problem grinding KOH flakes to very small pieces (not to a powder), in fact, it speeds up the dissolution of the KOH into the safrole, and if you are using the method where you suck any water out first, shouldn't pose a problem.

HOW TO SAFELY REDUCE THE VACUUM FROM A "SUCK-HARD" PUMP

take a thumbtack, the kind with the plastic head as opposed to the flat metal head, and stick it in the vacuum hose (close to the working end).  when you need less vacuum, pull the tack out.  when you want more, put it back in.  don't wiggle it around while it's in the hose, or it will make the hole too large and leak air into the system.
Nymphomania is not a disease  - its a goal!  (Methadist on Rosemary Kennedy)

[GOD]

and this will provide a consistant vacuum?  Swim doesnt wanna have to (re)vac distil his sass for each and every run 'cause hes gotta find starting temps.
Much appreciated with the replies, they will bee taken into account.

[Organikum]

* a capillary bubbling into your distillation flask (won't need any stirring anymore)

Thats it. OSMIUM is right this is the best solution, not to forget the advantages of less or no stirring. If you have a strong enough sucker this is a class A tip for most vacuum distillations and refluxes. No bumping and no boiling stones. Very smooth.
The capillary is easy selfmade. A glasstube heated with the torch and softly pulled on the ends. A capillary real means that there has to be a minimal opening left not only at the end but over a few centimeters. But it´s nonsense. Buy some of several diameter and invest your time somewhere else.  

In the long run you might consider a electronic rpm control for the pumps motor. You get such parts fucking cheap at surplus/auctionhouses.


ORGY

~ Love is the law, love under will. ~