careysub
International Hazard
Posts: 1339
Registered: 4-8-2014
Location: Coastal Sage Scrub Biome
Member Is Offline
Mood: Lowest quantum state
|
|
Get Your U.S. DBDMH While You Can!
A few months ago I set about to acquire some DBDMH (1,3-Dibromo-5,5-dimethylhydantoin) for use as a brominating agent, and a convenient source of pure
bromine - uncontaminated with chlorine.
I soon discovered that although it has been available very recently, it seemed nowhere to be found. Products that formerly contained it including ones
still advertised as being pure DBDMH, and products still listed as DBDMH in their current MSDS's turned out to be at best to be BCDMH
(1-Bromo-3-chloro-5,5-dimethylhydantoin) or even a mixture of this with 1,3-Dichloro-5,5-dimethylhydantoin.
"Bromo tabs" had become "chloro tabs with some bromine"!
I contacted several manufacturers and vendors to inquire about this, and all confirmed that their "bromo tab" products no longer contained any DBDMH,
and I could not find any old stock of the former product either.
But I have discovered one product still shipping that contains 99.4% DBDMH - Brilliance Sanitizer (NOT Brilliance Bromo Tabs). I waited until I
received the actual container to check (I had been burned a few times during this hunt) and sure enough it is labeled
1,3-Dibromo-5,5-dimethylhydantoin and nothing but (that 0.6% is unidentified).
Given the very recent rapid disappearance of DBDMH from products by all vendors, you might want to make use of the opportunity to lay in a supply of
DBDMH right now.
About that which we cannot speak, we must remain silent.
-Wittgenstein
Some things can never be spoken
Some things cannot be pronounced
That word does not exist in any language
It will never be uttered by a human mouth
- The Talking Heads
|
|
|
PirateDocBrown
National Hazard
Posts: 570
Registered: 27-11-2016
Location: Minnesota
Member Is Offline
Mood: No Mood
|
|
Good advice! I was picking up sodium bromide today and saw it, both on clearance sale due to winter. I'll have to go back.
|
|
|
Metacelsus
International Hazard
Posts: 2539
Registered: 26-12-2012
Location: Boston, MA
Member Is Offline
Mood: Double, double, toil and trouble
|
|
Can this be used instead of N-bromosuccinimide? I'm mostly thinking about allylic brominations. (Of course, the stoichiometry would be different.)
|
|
|
careysub
International Hazard
Posts: 1339
Registered: 4-8-2014
Location: Coastal Sage Scrub Biome
Member Is Offline
Mood: Lowest quantum state
|
|
Quote: Originally posted by Metacelsus  | | Can this be used instead of N-bromosuccinimide? I'm mostly thinking about allylic brominations. (Of course, the stoichiometry would be different.)
|
That's what I hear.
About that which we cannot speak, we must remain silent.
-Wittgenstein
Some things can never be spoken
Some things cannot be pronounced
That word does not exist in any language
It will never be uttered by a human mouth
- The Talking Heads
|
|
|
AvBaeyer
National Hazard
Posts: 651
Registered: 25-2-2014
Location: CA
Member Is Offline
Mood: No Mood
|
|
I have used DBDMH quite extensively and have previously mentioned the Brilliance product and its availablity on Amazon some time ago on this site. It
does not behave exactly as NBS though "mostly so." The imide bromine atom does generally react as NBS but the amide bound bromine atom may or may not
depending on conditions. There is quite a bit of literature on both DBDMH and DCDMH accessible via Google Scholar. Both of these agents behave in a
similar manner so information on one will generally apply to the other.
Below is some basic information from EROS. Unfortunately the structures did not paste but the descriptions and refs should be useful. Not mentioned
here is the bromination of ketones under extremely mild conditions and the mild oxidative cleavage of oximes and related ketone derivatives.
1,3-Dibromo-5,5-dimethylhydantoin
[77-48-5] · C5H6Br2N2O2 · 1,3-Dibromo-5,5-dimethylhydantoin · (MW 285.93)
(benzylic bromination of arenes; bromoperoxylation and bromofluorination of alkenes)
Alternate Names: DBH; 1,3-dibromo-5,5-dimethylimidazolidine-2,4-dione; dibromantin.
Physical Data: mp 197-199 °C (dec).
Solubility: slightly sol acetone, THF, 1,4-dioxane, H2O (hot), CCl4 (reflux).
Form Supplied in: white powder or crystals; widely available.
Analysis of Reagent Purity: determined by the standard iodide-thiosulfate titration method.
Preparative Methods: DBH has been prepared by reaction of Br2 (1 mol) with 5,5-dimethylhydantoin (0.5 mol) and NaOH (1 mol) in ice-water at 0 °C.1a
5,5-Dimethylhydantoin is widely available commercially, and can be prepared from KOCN, (NH4)2CO3, and acetone in water at 85 °C.1a After removal of
water and excess reagents by distillation, the resulting solution can be used directly for the preparation of DBH.
1,3-Dibromo-5-ethyl-5-methylhydantoin has also been prepared and has the advantage of greater solubility.1b
Purification: in an efficient fume hood (caution: bromine evolution), an impure sample of DBH (40 g) is dissolved as quickly as possible in 4 L of
preheated water at 90-95 °C. The solution is filtered if necessary, and the filtrate is then immediately chilled well in an ice bath to effect
crystallization. After most of the aqueous portion has been decanted, the white crystals are collected by filtration through a bed of ice and washed
with water. The crystals are dried in vacuo (63-70% recovery).1a
Handling, Storage, and Precautions: 1,3-dibromo-5,5-dimethylhydantoin should be stored refrigerated and protected from light and moisture to avoid
decomposition. DBH is an irritating solid and precautions should be taken to avoid inhalation of the powder or contact with skin.
Benzylic Bromination.
1,3-Dibromo-5,5-dimethylhydantoin has been used frequently for the radical bromination of benzylic positions of arenes and heterocycles. Using 0.5
molar equiv of DBH in CCl4 at reflux in the presence of Dibenzoyl Peroxide, high yields of the benzylic bromide are obtained under mild conditions.
The use of DBH has been found to be advantageous for the preparation of particularly acid-sensitive benzylic bromides, as shown in eqs 1 and 2.2,3 The
use of NBS in the former case affords a debenzoylated product, while in the latter example, elimination of AcOH and HBr leads to the aromatized
product. DBH was also found to be the most satisfactory reagent for the dehydrogenation of azlactones (eq 3).4
Electrophilic Bromination of Alkenes.
DBH is regularly substituted for N-Bromosuccinimide in industrial applications due to its low cost and high bromine content. Electrophilic
brominations of alkenes often proceed in higher yield using DBH, as shown for the bromohydration of synthesis of epoxides via bromohydrins (eq 4).5
DBH is the preferred reagent for the preparation of bromohydroperoxide precursors to 1,2-dioxetanes from alkenes using Hydrogen Peroxide.6 DBH has
also been found to be the most effective reagent for the bromofluorination of alkenes in combination with Hydrogen Fluoride-Pyridine complex or
Silicon(IV) Fluoride (eq 5).7 Alkynes can be converted to (E)-bromofluoroalkenes with good stereoselectivity; these are suitable substrates for
palladium-catalyzed coupling (eq 6).8 In an analogous sense to the use of N-Iodosuccinimide, DBH has been employed for the coupling of glycals to
alcohols affording 2-bromoglycosides which can be converted to 2-deoxyglycosides.9
Electrophilic Bromination of Thioethers.
The use of DBH for the deprotection of dithioacetals and dithianes has been found to be superior to many other methods. Transacetalation of dithianes
to diethyl acetals is achieved by treatment with 1 equiv of DBH in ethanol at rt.10 In addition, dithiolanes can be converted to the corresponding
geminal difluoro compounds in good yield by reaction with DBH and Pyridinium Poly(hydrogen fluoride) in dichloromethane at -78 °C.11
1. (a) Orazi, O. O.; Orio, O. A. Anales Asoc. Quím. Argentina 1953, 41, 153 (CA 1954, 48, 13 634c). (b) Orazi, O. O.; Corral, R. A.; Bonafede, J. D.
Anales Asoc. Quím. Argentina 1955, 43, 98 (CA 1956, 50, 10 071c).
2. Oakes, V.; Rydon, H. N.; Undheim, K. JCS 1962, 4678.
3. (a) Domínguez, D.; Ardecky, R. J.; Cava, M. P. JACS 1983, 105, 1608. (b) Ishizumi, K.; Ohashi, N.; Tanno, N. JOC 1987, 52, 4477.
4. Lott, R. S.; Breitholle, E. G.; Stammer, C. H. JOC 1980, 45, 1151.
5. (a) Coe, D. M.; Parry, D. M.; Roberts, S. M.; Storer, R. JCS(P1) 1991, 2373. (b) See also: Li, T. T.; Marx, M. CA 1984, 100, 120 584.
6. (a) Kopecky, K. R.; van de Sande, J. H.; Mumford, C. CJC 1968, 46, 25. (b) Richardson, W. H.; Stiggal-Estberg, D. L.; Chen, Z.; Baker, J. C.;
Burns, D. M.; Sherman, D. G. JOC 1987, 52, 3143. (c) Landis, M. E.; Lindsey, R. L.; Watson, W. H.; Zabel, V. JOC 1980, 45, 525.
7. (a) Eddarir, S.; Mestdagh, H.; Rolando, C. TL 1991, 32, 69. (b) Shimizu, M.; Nakahara, Y.; Yoshioka, H. CC 1989, 1881. (c) Chi, D. Y.; Kiesewetter,
D. O.; Katzenellenbogen, J. A.; Kilbourn, M. R.; Welch, M. J. JFC 1986, 31, 99.
8. Eddarir, S.; Mestdagh, H.; Rolando, C. TL 1991, 32, 69.
9. Tatsuta, K.; Tanaka, A.; Fujimoto, K.; Kinoshita, M.; Umezawa, S. JACS 1977, 99, 5826.
10. Muzard, M.; Portella, C. S 1992, 965.
11. Sondej, S. C.; Katzenellenbogen, J. A. JOC 1986, 51, 3508.
AvB
|
|
|
careysub
International Hazard
Posts: 1339
Registered: 4-8-2014
Location: Coastal Sage Scrub Biome
Member Is Offline
Mood: Lowest quantum state
|
|
Thanks, and so you did on this thread:
https://www.sciencemadness.org/whisper/viewthread.php?tid=52...
(I now find).
The specific references on use are very valuable, thanks again (I was going to try dig some up but do not need to now, if I could even have done as
good a job.)
But the disappearance of DBDMH from nearly all products that recently contained it is real, confirmed by manufacturers, and I am able to confirm that
the spa sanitizer is still pure DBDMH at this time. It would be unwise to assume that it will remain immune to this pattern.
About that which we cannot speak, we must remain silent.
-Wittgenstein
Some things can never be spoken
Some things cannot be pronounced
That word does not exist in any language
It will never be uttered by a human mouth
- The Talking Heads
|
|
|
j_sum1
Administrator
Posts: 6324
Registered: 4-10-2014
Location: At home
Member Is Online
Mood: Most of the ducks are in a row
|
|
I have not even seen DBDMH in Australia -- just the chloro-bromo cousin, 1-Bromo-3-chloro-5,5-dimethylhydantoin. As far as I know that is the only
OTC source of bromine available around here and it did not seem useful enough to spend money on. So, I concur, pick up some of the DBDMH while you
can.
|
|
|
FireLion3
Hazard to Others
Posts: 218
Registered: 11-1-2014
Member Is Offline
Mood: No Mood
|
|
The brilliance product for years now has been the only product I could ever find with DBDMH, both online and locally. Every other product has always
seemed to be the bromo chloro.
|
|
|
Melgar
Anti-Spam Agent
Posts: 2004
Registered: 23-2-2010
Location: Connecticut
Member Is Offline
Mood: Estrified
|
|
Len's book (Small-Scale Synthesis of Laboratory Reagents) describes the preparation of bromine from the chloro/bromo version using sodium
metabisulfite. Apparently, this reaction is quite selective for bromine, it being 95% of the crude product. So I wouldn't say the chloro/bromo
version is totally useless.
|
|
|
clearly_not_atara
International Hazard
Posts: 2789
Registered: 3-11-2013
Member Is Offline
Mood: Big
|
|
What's the point of this? CBDMH is decidedly inferior for hot tubs (any chlorine is bad in a hot tub, although as long as [Br] > [Cl] you're ok)
and it isn't even that much harder to get bromine from if you're up to evil stuff like trying to make your own fluorescent crystals or something.
Politician's syllogism, I guess.
|
|
|
Loptr
International Hazard
Posts: 1348
Registered: 20-5-2014
Location: USA
Member Is Offline
Mood: Grateful
|
|
It is very hard to find. I went to purchase some more and it disappeared from my bookmarks.
These guys seem to still have some.
https://www.gritzpools.com/product/brilliance-for-spas-sanit...
https://www.allaboutspas.com/Brilliance-Sanitizer-1-5-lb-Bot...
"Question everything generally thought to be obvious." - Dieter Rams
|
|
|
AvBaeyer
National Hazard
Posts: 651
Registered: 25-2-2014
Location: CA
Member Is Offline
Mood: No Mood
|
|
Loptr,
Thanks for the heads up! I think I just ordered the last bottles from All About Spas. Too bad it may be gone as it is so useful for brominations
without having to fool with elemental bromine.
AvB
Got a call today from the New Mexico supplier - DBDMH has been discontinued by the manufacturer and they are out of stock so my order will be
cancelled. No reason given by the manufacturer as to why the product has been discontinued. The substitute is the "dichlorinating granules" or a
product which contains the "dichlorinating granules with added sodium bromide."
I do know that the company in Georgia that made DBDMH was sold to Lonza.
Overall, bad news.
AvB
[Edited on 31-12-2018 by AvBaeyer]
|
|
|
Loptr
International Hazard
Posts: 1348
Registered: 20-5-2014
Location: USA
Member Is Offline
Mood: Grateful
|
|
| Quote: Originally posted by AvBaeyer | Loptr,
Thanks for the heads up! I think I just ordered the last bottles from All About Spas. Too bad it may be gone as it is so useful for brominations
without having to fool with elemental bromine.
AvB
Got a call today from the New Mexico supplier - DBDMH has been discontinued by the manufacturer and they are out of stock so my order will be
cancelled. No reason given by the manufacturer as to why the product has been discontinued. The substitute is the "dichlorinating granules" or a
product which contains the "dichlorinating granules with added sodium bromide."
I do know that the company in Georgia that made DBDMH was sold to Lonza.
Overall, bad news.
AvB
[Edited on 31-12-2018 by AvBaeyer] |
Yeah, same here. The call was from Roswell, NM. I saw the caller id and thought about making an alien joke while picking up...
I just placed an order with the first site.
Edit: here is another
Brilliance Sanitizer (Bromine)
https://www.mnspasdirect.com/brilliance-sanitizer-bromine/
[Edited on 31-12-2018 by Loptr]
https://www.thepoolguystore.com/Brilliance-for-spas-Sanitize...
[Edited on 1-1-2019 by Loptr]
https://shop.arvidsons.com/products/brilliance-for-spas-sani...
[Edited on 1-1-2019 by Loptr]
[Edited on 1-1-2019 by Loptr]
"Question everything generally thought to be obvious." - Dieter Rams
|
|
|
Loptr
International Hazard
Posts: 1348
Registered: 20-5-2014
Location: USA
Member Is Offline
Mood: Grateful
|
|
The gritz pools link still has it available.
I hadn't heard anything back from them and suddenly I got a delivery scheduled for today notification. 5lbs 
"Question everything generally thought to be obvious." - Dieter Rams
|
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
