SODIUM BROMIDE 1
Sodium Bromide generated by reaction of NaBr with Chlorine, Chloramine-T,
or N-Chlorosuccinimide.7 This procedure allows the preparation
of radiobrominated organic compounds from radioactive NaBr.
NaBr
Sodium bromide is useful as an electrolyte in electrochemical
oxidations, generating electrophilic bromine species which can
[7647-15-6] BrNa (MW 102.89)
react with organic substrates. Under suitable conditions, alkenes
InChI = 1/BrH.Na/h1H;/q;+1/p-1/fBr.Na/h1h;/q-1;m
are epoxidized,8 alcohols are oxidized,9 and methyl ketones are
InChIKey = JHJLBTNAGRQEKS-FBXYEDMECF
converted to methyl esters.10
(source of bromide ion as nucleophile; precursor to bromine
Miscellaneous Uses. Raney Nickel modified with tartaric acid
electrophiles)
and NaBr is an inexpensive catalyst, suitable for the large-scale
ć%
Physical Data: mp 755 C; d 3.21 g cm-3.
reduction of methyl ketones and 1,3-dicarbonyl compounds to
Solubility: very sol water; sol methanol, ethanol.
optically active alcohols in moderate enantiomeric excesses.11
Form Supplied in: colorless, odorless crystals, granules, or
powder.
ć%
Drying: is hygroscopic and should be dried at 140 C for appli-
1. (a) Buchman, E. R.; Deutsch, D. H.; Fujimoto, G. I., J. Am. Chem. Soc.
cations that require the anhydrous salt.
1953, 75, 6228. (b) Cason, J.; Correia, J. S., J. Org. Chem. 1961, 26,
Handling, Storage, and Precautions: should be taken directly
3645. (c) Herzog, H. L., Org. Synth., Coll. Vol. 1963, 4, 753.
from the oven when dryness is required. NaBr is of low toxicity.
2. (a) Willy, W. E.; McKean, D. R.; Garcia, B. A., Bull. Chem. Soc. Jpn.
1976, 49, 1989. (b) Babler, J. H.; Spina, K. P., Synth. Commun. 1984,
14, 1313.
3. Singhal, G. M.; Zaman, S. S.; Sharma, R. P., Chem. Ind. (London) 1991,
Source of Bromide Nucleophile. Sodium bromide is an in- 687.
expensive source of bromide anion for service as a nucleophile or
4. (a) Ahmad, S.; Khan, M. A.; Iqbal, J., Synth. Commun. 1988, 18, 1679.
(b) Iqbal, J.; Khan, M. A., Synth. Commun. 1989, 19, 515.
nucleophilic catalyst. In alcoholic and dipolar aprotic solvents,
NaBr converts the sulfonate esters of primary and secondary 5. (a) Morimoto, T.; Hirano, M.; Ashiya, H.; Egashira, H.; Zhuang, X.,
Bull. Chem. Soc. Jpn. 1987, 60, 4143. (b) Morimoto, T.; Hirano, M.;
alcohols to the corresponding alkyl bromides.1 Sodium bromide
Hamaguchi, T.; Shimoyama, M.; Zhuang, X., Bull. Chem. Soc. Jpn. 1992,
cleanly converts primary alkyl chlorides to bromides, provided
65, 703.
that a large excess of ethyl bromide or dibromomethane is added
6. (a) Kajigaeshi, S.; Nakagawa, T.; Fujisaki, S.; Nishida, A.; Noguchi, M.,
as a chloride ion scavenger.2 In the presence of Dowex-50 ion
Chem. Lett. 1984, 713. (b) Kajigaeshi, S.; Nakagawa, T.; Nagasaki, N.;
exchange resin, NaBr opens epoxides to bromohydrins.3 Bromo-
Fujisaki, S., Synthesis 1985, 674.
trimethylsilane can be generated in situ from Chlorotrimethylsi-
7. (a) Kabalka, G. W.; Sastry, K. A. R.; Knapp, F. F.; Srivastava, P. C.,
lane and NaBr, and then used to convert aldehydes and ketones to
Synth. Commun. 1983, 13, 1027. (b) Kabalka, G. W.; Sastry, K. A. R.;
silyl enol ethers under mild conditions with significant regio- and
Hsu, H. C.; Hylarides, M. D., J. Org. Chem. 1981, 46, 3113.
stereoselectivity.4
8. (a) Torii, S.; Uneyama, K.; Ono, M.; Tazawa, H.; Matsunami, S.,
Tetrahedron Lett. 1979, 48, 4661. (b) Torii, S.; Uneyama, K.; Matsunami,
S., J. Org. Chem. 1980, 45, 16.
Precursor to Bromine Electrophiles. Chemical or electro-
9. Inokuchi, T.; Matsumoto, S.; Torii, S., J. Org. Chem. 1991, 56, 2416.
chemical oxidation of sodium bromide generates reactive elec-
10. Nikishin, G. I.; Elinson, M. N.; Makhova, I. V., Angew. Chem., Int. Ed.
trophilic bromine species, which can effect a variety of useful
Engl. 1988, 27, 1716.
transformations. A mixture of NaBr and Peracetic Acid oxidizes
11. (a) Ito, K.; Harada, T.; Tai, A.; Izumi, Y., Chem. Lett. 1979, 1049. (b) Ito,
secondary alcohols to ketones, primary benzylic alcohols to alde-
K.; Harada, T.; Tai, A., Bull. Chem. Soc. Jpn. 1980, 53, 3367. (c) Harada,
hydes, primary aliphatic alcohols to dimeric esters, and Ä…,É-diols
T.; Yamamoto, M.; Onaka, S.; Imaida, M.; Ozaki, H.; Tai, A.; Izumi, Y.,
to lactones.5 The reaction conditions, which appear to involve the Bull. Chem. Soc. Jpn. 1981, 54, 2323. (d) Tai, A.; Harada, T.; Hiraki,
Y.; Murakami, S., Bull. Chem. Soc. Jpn. 1983, 56, 1414. (e) Osawa. T.;
formation of acetyl hypobromite, provide an inexpensive and less
Harada, T.; Tai, A., J. Catal. 1990, 121, 7. (f) Sugimura, T.; Yoshikawa,
toxic alternative to chromium oxidants. By combining NaBr and
M.; Yoneda, T.; Tai, A., Bull. Chem. Soc. Jpn. 1990, 63, 1080.
NaBrO2, it is possible to generate hypobromite ion without us-
ing elemental bromine. This mixture of salts effects the Hofmann
James S. Nowick
degradation of primary amides to generate amines and promotes
University of California, Irvine, CA, USA
the bromoform reaction of methyl ketones to generate carboxylic
acids.6 Organoboranes are brominolyzed to bromoalkanes or bro-
Guido Lutterbach
moalkenes upon treatment with bromine chloride, which can be
Johannes Gutenberg University, Mainz, Germany
Avoid Skin Contact with All Reagents