Author Topic: performic oxidation & boro reduction  (Read 1522 times)

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El_Zorro

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performic oxidation & boro reduction
« on: April 07, 2002, 06:07:00 PM »
Just a few Q's relating to the performic.

1.Does formic acid form an azeotrope(sp.?) with water?  As in reacting sodium formate with HCl, or H3PO4, then distilling?  Could pure formic be isolated by simple distillation?

2.After the glycolization step in the performic, the products are mostly the monoformyl glycol, correct?  So would the strong acid hydrolysis give the ketone and formic acid, among other things?

3.Anyone have ref's for using an acid besides sulfuric for the hydrolysis step?


And now for the boro reduction.

1.Couldn't the boro be dissolved in anhydrous methanol and dripped in, so you wouldn't have to sit around for fucking HOURS dropping it in teaspoon by teaspoon.  All you would have to do is maintain strong stirring and adjust the drip rate to keep the temp acceptable.  Could it work?

Well, that's the only question for the boro bit, but can anyone give me some insights?

Edit: Oh, shit!  I was just looking up the density of formic on chemfinder, and it said the boiling point was 100.7.  Shit!  I don't entirely trust chemfinder, though, so somebody, please, tell me it aint so!


I sell crack for the CIA :(

LaBTop

  • Guest
Answers
« Reply #1 on: April 07, 2002, 06:23:00 PM »
1.Yes, but you don't have to worry about that, the buffered performic doesn't need distillation of formic acid.
2.Yes, and if done well, you should get a near quantitative yield of monoformyl glycol, the 15% H2SO4 treatment is the culprit, if done too hot or too long, many sideproducts (2 to 2.5 hrs max), if done to short or too cold, not enough conversion to ketone.
3.Yes, but that will come up soon, when consistent yields have been obtained. The Hive laboratories Inc. is working on it, hehhe.

1.No. Don't even try it, boro reacts with methanol. LT/

WISDOMwillWIN

Rhodium

  • Guest
And as always, my page...
« Reply #2 on: April 07, 2002, 06:45:00 PM »
What you need to know about the modified performic acid oxidation:

https://www.thevespiary.org/rhodium/Rhodium/chemistry/peracid.html


El_Zorro

  • Guest
Just the guys I was lookin' for!
« Reply #3 on: April 07, 2002, 08:10:00 PM »
LaBTop-

1.What do you mean?  If I react sodium formate with the acid of my choice, I would think that it would need some cleanup before the reaction.
2.With the monoformyl glycol bit, I was just wondering if the formic acid could be distilled and reused, eliminating a precurser for future reactions.  I realize the yeild losses lie in the hydrolyzation step, I've been following your work. ;)
3.Maybe someday there'll be a quantitative safrole oxidation. ;D

4.Then why is methanol used?  Wouldn't it tie up boro that should go to the imine?  I guess I'm just a fatass and want to do as little work as possible. ::)


And Rhod-

I could probably recite that page by heart by now.  Your page is always the first place I look, next to the Hive.

Anyone-

Is formic's BP really 100.7 °C?  That would be a bitch to distill from water. >:(

I sell crack for the CIA

cheeseboy

  • Guest
eww
« Reply #4 on: April 07, 2002, 11:14:00 PM »
Plus cheese heard that Formic acid is nasty smelling and it takes a coon's age to distill. Is H2SO4 hard for you to get EZ or do you have an excess of other 'strong' acids you want to use up?

May De Sorce Bee Wit Chu-Always

LaBTop

  • Guest
Answers:
« Reply #5 on: April 08, 2002, 01:01:00 AM »
1. Keep that sodium formate in a safe, and guard it as a diamond, for better days to come. Formic acid can be obtained from beekeepers.
2. Don't even concider it.
3. Yes, there will be.
4. It's the needed solvent to let the reaction proceed, the boro hitting it when spooned in is directly used for the good work, but if stocked up in a dripping funnel all together with an amount of methanol, it will decompose fairly fast, and your yield will be near zero.
Btw, endless discussions on this topic can be found in TFSE.

BP formic acid: fill in Formic acid in Chemfinder search, then note the CAS number at their page only, do NOT pay attention to their crappy data, then click Physical Properties, then you get a new screenshot, click there the first top long link to InternationalPhysicalProperties Data, it's the first link on top, then fill in there -only the CAS number- (like 11-22-33 as an example only, not all those 0000 in front of them from Chemfinder), and these guys have reliable data!
I found a bp of a chem yesterday in Chemfinder which was about 200C OFF the real one in IPP! Messy data. LT/


WISDOMwillWIN

El_Zorro

  • Guest
how's this for a meaningful subject??
« Reply #6 on: April 08, 2002, 12:43:00 PM »
cheese-

I could get H2SO4, but I was only intersted in the yeild side of the equation.

LaBTop-

1.Why is sodium formate so precious?  Are you preparing for formic becoming a List 1? ;)

2.Why not?  Does it have to do with what cheese mentioned before, smell and time?

3.Let's hope so.

I sell crack for the CIA

El_Zorro

  • Guest
how about this whimsical idea?
« Reply #7 on: April 14, 2002, 02:20:00 PM »

El_Zorro

  • Guest
touche
« Reply #8 on: April 14, 2002, 06:13:00 PM »
after U'ingTFSE, All I could come up with was [No 209961], which said that the acetate ion is used to buffer the reaction somewhat.  I found this post by searching for "methylammonium acetate", and when I searched for "methylamine acetate", TFSE found two posts, but they wouldn't come up.  Has anybee actually tried using methylammonium acetate in the boro reduction?

Do not go gentle into that good night.  Rage, Rage, against the dying of the light.  --Dylan Thomas

Rhodium

  • Guest
Freebase
« Reply #9 on: April 14, 2002, 06:46:00 PM »
The methylamine freebase must be used, as the acetate ion would react with the sodium borohydride if it was left in solution. However, something that has been used successfully in the past is an equimolar mixture of methylamine hydrochloride and triethylamine, which in solution creates methylamine freebase and triethylamine hydrochloride.

Post 188868 (missing)

(SuperAssman: "Repost: BzCl ---> meth    (for "Andrew"??)", Stimulants)

El_Zorro

  • Guest
I guess there is no lazy way.[frown]
« Reply #10 on: April 14, 2002, 07:03:00 PM »
Thanks anyway, but I was looking for more along the lines of a methylamine salt that could actually be used in the boro.  I just don't wanna have to dick around with the freebase.

Do not go gentle into that good night.  Rage, Rage, against the dying of the light.  --Dylan Thomas