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All 15 posts Subject: Bromination with NaBr and Oxone Please login to post Down

Vibrating_Lights
(Hive Addict)
08-23-02 08:54
No 348051
      Bromination with NaBr and Oxone

Recently Rhodium posted about para Clorinations with NaCl and Oxone i believe. Will oxone Convert NaBr into Br2 or is it nescesary to first produce HBr Like with an I2 extraction with HCl/H2O2.. would it be wise to try a 2 phase bromination by dissolving 2CH freebase in DCM and addin (aq) Oxone to an (Aq) solution of NaBr??? or even better collect Br2 In DCm wash with Bicarb the combine with 2CH.???
So much game I could sell a hooker some pussy
Vl_

Chromic
(Synaptic Self-Mutilator)
08-23-02 14:09
No 348105
      Best way

The best way to brominate aromatic rings with KBr (or an equivilant of NaBr) as the source is via a reference that Osmium gave to brominate vanillin. What are you planning to brominate?

Here's the general idea:

Prepare 120ml of GAA, 40ml H2O, 11.8g H2SO4 (120mmol), 14.3g KBr (120mmol) and 5.8g 35% H2O2 (60mmol) in a container. Stir and watch as the solution turns orange-red as the bromine is formed, and it starts to smell like bleach.

Dissolve 100mmol of freebase (or hydrochloride, shouldn't matter either way) into 50ml GAA in a flask. Cool this in an icebath. Then drip in the Br2 solution from the container. Once this is done, slowly drip in 5.8g 35% H2O2 (60mmol). Basify the whole thing, extract and work up as usual.

The overall reaction goes as follows:
A + H2O2 + KBr + H+ ==> Br-A + 2 H2O + K+

Of course, there's a few separate reactions going on:

in the container:
1) H2O2 + 2 KBr + H+ ==> Br2 + H2O + K+
in the flask:
2) A + Br2 ==> Br-A + Br-
3) H2O2 + 2 Br- + H+ ==> Br2 + H2O (then back to rxn 2 with the Br2, until most all the Br- is used up)

I've done this on PMA, and I'm unsure if it works exactly as stated as the Br-PMA seemed to have pretty much the same effect as the starting material, so caveat emptor.

Vibrating_Lights
(Hive Addict)
08-23-02 20:42
No 348212
      chromic

2CH
So much game I could sell a hooker some pussy
Vl_

Chromic
(Synaptic Self-Mutilator)
08-23-02 21:55
No 348221
      Yeah, I read that.

Yeah, I read that.

The above procedure is for 100mmol of aromatic you want to brominate. DMMDA-2, PMA, MDA, 2C-H, vanillin, whatever... it will work for any of it, and making bromine in situ is a blessing compared to handling liquid bromine.

Good luck!

slothrop
(Newbee)
08-24-02 00:20
No 348265
      Bromination with NaBr and Oxone
(Rated as: excellent)

Recently Rhodium posted about para Clorinations with NaCl and Oxone i believe. Will oxone Convert NaBr into Br2 or is it nescesary to first produce HBr Like with an I2 extraction with HCl/H2O2.. would it be wise to try a 2 phase bromination by dissolving 2CH freebase in DCM and addin (aq) Oxone to an (Aq) solution of NaBr??? or even better collect Br2 In DCm wash with Bicarb the combine with 2CH.???

SYNTHETIC COMMUNICATIONS
Vol.32,No.15,pp.2313 –2318,2002

AN EFFICIENT AND REGIOSELECTIVE
OXYBROMINATION OF AROMATIC
COMPOUNDS USING POTASSIUM
BROMIDE AND OXONE

General Procedure for the Bromination of Aromatic Compounds:
Oxone (2.2 mmol) was added to a well stirred solution of KBr
(2.2 mmol) and substrate (2.0 mmol) in methanol (10 mL) and the reaction
mixture was allowed to stir at room temperature. The reaction was
monitored by thin layer chromatography (TLC).After the completion of
the reaction.The mixture was ﬁltered and solvent evaporated under reduced
pressure.The products were puri ﬁed by column chromatography over silica
gel and confirmed by HNMR and Mass spectra.

Parasubsts are dominating and generally > 70 %

//Tyrone Slothrop

Mindflux
(Stranger)
08-24-02 01:26
No 348284
      nice!

This is the greatest thing since sliced bread laugh

Chromic
(Synaptic Self-Mutilator)
08-24-02 01:39
No 348289
      What?

Why is oxone better than H2O2/H2SO4? But... if the above reference is correct, there's no need for brominations to be done in acetic acid, and methanol will suffice. (that's good news!)

Any opinions?

Vibrating_Lights
(Hive Addict)
08-24-02 09:05
No 348444
      everything

I bet this will also work with KCl And KI too. We will call this the easy analog maker.
VL_
So much game I could sell a hooker some pussy
Vl_

cilliersb
(Hive Bee)
08-26-02 12:27
No 349161
      Maybe

It cill work for KCl, but not for KI.

H2SO4 can not form HI when reacting with KI, but will form HCl when reacted with NaCl. H2O2 will produce free I2 from HI and free Cl2 from HCl, but getting to HI from NaI or KI is the problem.

Rather use NIS for your Iodinations, elemental I2 will not work anyway.

Osmium
(Stoni's sexual toy)
08-26-02 16:26
No 349216
User Picture       > H2SO4 can not form HI when reacting with KI ...

> H2SO4 can not form HI when reacting with KI

It should work as long as the concentrations aren't too high.
I'm not fat just horizontally disproportionate.

moo
(Hive Bee)
08-26-02 18:15
No 349237
      Iodinations

What has HI got to do with the subject? Isn't the H₂SO₄ supposed to catalyze the oxidation (H₂O₂ + 2H⁺ + 2e^- --> 2H₂O)? Furthermore, there are many examples of I₂ + oxidising agent aromatic iodinations, including H₂O₂, peracetic acid, HNO₃ and its salts, NO₂ and KMnO₄. (Goddamn, if there were no subscript tags it would take a lot less time to write a post! laugh )

Mindflux
(Stranger)
08-26-02 23:35
No 349326
      Dont forget silver sulfate

https://www.rhodium.ws/chemistry/doisynth.html

lugh
(Moderator)
08-31-02 21:55
No 351083
      Following Paper

I bet this will also work with KCl And KI too. We will call this the easy analog maker.

Since the following paper the paper cited by slothrop by the Narender group is on iodination using KI and oxone, you are definitely correct laugh

Rhodium
(Chief Bee)
09-02-02 22:37
No 351978
User Picture       Aromatic iodination

And here it is: https://www.rhodium.ws/chemistry/oxone.aromatic.iodination.html

Rhodium
(Chief Bee)
10-05-04 01:52
No 534473
      Aromatic Bromination: Ammonium bromide + Oxone
(Rated as: good read)

Mild and regioselective oxidative bromination of aromatic compounds using ammonium bromide and oxone
N. Narender, K.V.V. Krishna Mohan, S.J. Kulkarni and K.V. Raghavan
J. Chem. Research (S), 597-598 (2003) (https://www.rhodium.ws/pdf/aromatic.bromination.oxone.nh4br.pdf)

Abstract
The selective mono-bromination of various activated aromatic compounds is reported using in situ generated bromine from NH₄Br as a bromine source and oxone as an oxidant for the first time.

^{The Hive - Clandestine Chemists Without Borders}

	https://the-hive.archive.erowid.org	the-hive@erowid.org



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	All 15 posts		Subject: Bromination with NaBr and Oxone		Please login to post		Down


		Vibrating_Lights (Hive Addict) 08-23-02 08:54 No 348051				Bromination with NaBr and Oxone
						Recently Rhodium posted about para Clorinations with NaCl and Oxone i believe. Will oxone Convert NaBr into Br2 or is it nescesary to first produce HBr Like with an I2 extraction with HCl/H2O2.. would it be wise to try a 2 phase bromination by dissolving 2CH freebase in DCM and addin (aq) Oxone to an (Aq) solution of NaBr??? or even better collect Br2 In DCm wash with Bicarb the combine with 2CH.??? So much game I could sell a hooker some pussy Vl_



		Chromic (Synaptic Self-Mutilator) 08-23-02 14:09 No 348105				Best way
						The best way to brominate aromatic rings with KBr (or an equivilant of NaBr) as the source is via a reference that Osmium gave to brominate vanillin. What are you planning to brominate? Here's the general idea: Prepare 120ml of GAA, 40ml H2O, 11.8g H2SO4 (120mmol), 14.3g KBr (120mmol) and 5.8g 35% H2O2 (60mmol) in a container. Stir and watch as the solution turns orange-red as the bromine is formed, and it starts to smell like bleach. Dissolve 100mmol of freebase (or hydrochloride, shouldn't matter either way) into 50ml GAA in a flask. Cool this in an icebath. Then drip in the Br2 solution from the container. Once this is done, slowly drip in 5.8g 35% H2O2 (60mmol). Basify the whole thing, extract and work up as usual. The overall reaction goes as follows: A + H2O2 + KBr + H+ ==> Br-A + 2 H2O + K+ Of course, there's a few separate reactions going on: in the container: 1) H2O2 + 2 KBr + H+ ==> Br2 + H2O + K+ in the flask: 2) A + Br2 ==> Br-A + Br- 3) H2O2 + 2 Br- + H+ ==> Br2 + H2O (then back to rxn 2 with the Br2, until most all the Br- is used up) I've done this on PMA, and I'm unsure if it works exactly as stated as the Br-PMA seemed to have pretty much the same effect as the starting material, so caveat emptor.



		Vibrating_Lights (Hive Addict) 08-23-02 20:42 No 348212				chromic
						2CH So much game I could sell a hooker some pussy Vl_



		Chromic (Synaptic Self-Mutilator) 08-23-02 21:55 No 348221				Yeah, I read that.
						Yeah, I read that. The above procedure is for 100mmol of aromatic you want to brominate. DMMDA-2, PMA, MDA, 2C-H, vanillin, whatever... it will work for any of it, and making bromine in situ is a blessing compared to handling liquid bromine. Good luck!



		slothrop (Newbee) 08-24-02 00:20 No 348265				Bromination with NaBr and Oxone (Rated as: excellent)
						Recently Rhodium posted about para Clorinations with NaCl and Oxone i believe. Will oxone Convert NaBr into Br2 or is it nescesary to first produce HBr Like with an I2 extraction with HCl/H2O2.. would it be wise to try a 2 phase bromination by dissolving 2CH freebase in DCM and addin (aq) Oxone to an (Aq) solution of NaBr??? or even better collect Br2 In DCm wash with Bicarb the combine with 2CH.??? SYNTHETIC COMMUNICATIONS Vol.32,No.15,pp.2313 –2318,2002 AN EFFICIENT AND REGIOSELECTIVE OXYBROMINATION OF AROMATIC COMPOUNDS USING POTASSIUM BROMIDE AND OXONE General Procedure for the Bromination of Aromatic Compounds: Oxone (2.2 mmol) was added to a well stirred solution of KBr (2.2 mmol) and substrate (2.0 mmol) in methanol (10 mL) and the reaction mixture was allowed to stir at room temperature. The reaction was monitored by thin layer chromatography (TLC).After the completion of the reaction.The mixture was ﬁltered and solvent evaporated under reduced pressure.The products were puri ﬁed by column chromatography over silica gel and confirmed by HNMR and Mass spectra. Parasubsts are dominating and generally > 70 % //Tyrone Slothrop



		Mindflux (Stranger) 08-24-02 01:26 No 348284				nice!
						This is the greatest thing since sliced bread



		Chromic (Synaptic Self-Mutilator) 08-24-02 01:39 No 348289				What?
						Why is oxone better than H2O2/H2SO4? But... if the above reference is correct, there's no need for brominations to be done in acetic acid, and methanol will suffice. (that's good news!) Any opinions?



		Vibrating_Lights (Hive Addict) 08-24-02 09:05 No 348444				everything
						I bet this will also work with KCl And KI too. We will call this the easy analog maker. VL_ So much game I could sell a hooker some pussy Vl_



		cilliersb (Hive Bee) 08-26-02 12:27 No 349161				Maybe
						It cill work for KCl, but not for KI. H2SO4 can not form HI when reacting with KI, but will form HCl when reacted with NaCl. H2O2 will produce free I2 from HI and free Cl2 from HCl, but getting to HI from NaI or KI is the problem. Rather use NIS for your Iodinations, elemental I2 will not work anyway.



		Osmium (Stoni's sexual toy) 08-26-02 16:26 No 349216				> H2SO4 can not form HI when reacting with KI ...
						> H2SO4 can not form HI when reacting with KI It should work as long as the concentrations aren't too high. I'm not fat just horizontally disproportionate.



		moo (Hive Bee) 08-26-02 18:15 No 349237				Iodinations
						What has HI got to do with the subject? Isn't the H₂SO₄ supposed to catalyze the oxidation (H₂O₂ + 2H⁺ + 2e^- --> 2H₂O)? Furthermore, there are many examples of I₂ + oxidising agent aromatic iodinations, including H₂O₂, peracetic acid, HNO₃ and its salts, NO₂ and KMnO₄. (Goddamn, if there were no subscript tags it would take a lot less time to write a post!)



		Mindflux (Stranger) 08-26-02 23:35 No 349326				Dont forget silver sulfate
						https://www.rhodium.ws/chemistry/doisynth.html



		lugh (Moderator) 08-31-02 21:55 No 351083				Following Paper
						I bet this will also work with KCl And KI too. We will call this the easy analog maker. Since the following paper the paper cited by slothrop by the Narender group is on iodination using KI and oxone, you are definitely correct



		Rhodium (Chief Bee) 09-02-02 22:37 No 351978				Aromatic iodination
						And here it is: https://www.rhodium.ws/chemistry/oxone.aromatic.iodination.html



		Rhodium (Chief Bee) 10-05-04 01:52 No 534473				Aromatic Bromination: Ammonium bromide + Oxone (Rated as: good read)
						Mild and regioselective oxidative bromination of aromatic compounds using ammonium bromide and oxone N. Narender, K.V.V. Krishna Mohan, S.J. Kulkarni and K.V. Raghavan J. Chem. Research (S), 597-598 (2003) (https://www.rhodium.ws/pdf/aromatic.bromination.oxone.nh4br.pdf) Abstract The selective mono-bromination of various activated aromatic compounds is reported using in situ generated bromine from NH₄Br as a bromine source and oxone as an oxidant for the first time. ^{The Hive - Clandestine Chemists Without Borders}

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