Guys i can't believe it but since this obviously isn't on Rhodium's site as well as non-TFSEable i assume it hasn't been covered.
Ah, this lovely TFSE - it brings about such a wonderful wealth of info as well as ever-present fear of being ridiculed
...
I just followed the ref that Cherrie Baby posted, the US patent #2553518.
The authors state this as a general procedure for convertion of any mono- or poly- chlorinated alkane or cycloalkane to the respective bromides. This is achieved through bubbling HBr into chloroalkane and some AlBr3 or AlCl3 at RT , although higher temps are also of use. The Al bromide can bee made in situ from Al powder (for those fond of Friedel-Crafts: this looks like an easy way to make anh. AlCl3
)
This is sort of a digest procedure from examples 3 and 6 (that's 'cause #6's only purpose is to show that AlBr3 can bee generated in situ and in the rest they use ready AlCl3/AlBr3)
Gaseous HBr is bubbled through a suspension of 2,7 g of Al powder in 239 g CHCl3 until the weight of HBr passed in is 289 g. Al promptly dissolves in the beginning of the addition. The rxn is then washed w/water, dryed and analyzed. It was found to consist of 2% unreacted chloroform, 15% CHBrCl2, 40,9% CHBr2Cl and 41,2 CHBr3.
Antoncho