Sciencemadness Discussion Board

Get Your U.S. DBDMH While You Can!

careysub - 27-12-2016 at 22:39

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.

PirateDocBrown - 28-12-2016 at 03:29

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 - 28-12-2016 at 06:04

Can this be used instead of N-bromosuccinimide? I'm mostly thinking about allylic brominations. (Of course, the stoichiometry would be different.)

careysub - 28-12-2016 at 07:50

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.

AvBaeyer - 28-12-2016 at 16:26

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 - 28-12-2016 at 17:29

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.

j_sum1 - 28-12-2016 at 18:03

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 - 28-12-2016 at 18:58

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 - 30-12-2016 at 20:27

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 - 30-12-2016 at 21:02

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 - 30-12-2018 at 13:04

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...

AvBaeyer - 30-12-2018 at 20:41

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 - 31-12-2018 at 11:20

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...:P

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]

Loptr - 3-1-2019 at 07:07

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 :)