Add Triethylamine, excess benzylbromide will get converted to Benzyltriethyl ammonium bromide which is water soluble. Partition between water and any organic solvent will solve the problem.

benzyl bromide can be remove by distillation under reduce pressure at appropriate temp, or you may try fractional distillation 

Yup tried it, it didn't worked out, still benzyl bromide is left 

If your product is soluble in organic solvents have you tried doing a silica gel column?  A TLC would tell you if you can separate the reaction components, you may just need to play around with different eluent systems (hexane:EtOAc or DCM:MeOH maybe).  If not, depending on the functionality in your molecule (amine/carboxylic acid?) you may be able to extract your product into an acid/base solution and then wash out the benzyl bromide with an organic solvent.  Failing that have you tried running the reaction without excess BnBr?  Hope this is useful!

I have tried using equimolar conc of the benzyl bromide, but the reaction didn't complete, so we need to take little higher concentration of benzyl bromide. I have successfully separated it by using column chromatography, but i was looking if it is possible to get rid of this by any work up procedure. And product cannot be transformed for extracting in acid/basic solution.

When we are performing the reaction on small scale (100mg) then it can be removed under reduced pressure and elevated temperature, but on larger scale (>1g), much of benzyl bromide remains in the reaction mixture.

Dear Ramit, unfortunately, I think the best way is to go to silica gel column. Hardly you will escape from this...

I guess this is the only way left... otherwise there must be some way..

You can convert benzyl bromide into dimethylbenzylamine and wash with dilute HCl.

Perhaps you could adsorb your product on an acidic or basic solid phase. Or you could extract benzyl bromide on C18-silica, leaving product in the eluent. Is crystallization an option? what mobile phase was used for the column? what is the order of elution?

if your crud product is still solid at room temp you can try slurry wash with Diisopropyl ether (initially check whether it is soluble in it or not) or even mixture of some low polar solvents,  filter it and then keep the product under high vacuum over night.

silica gel coloumn in dichloromethane. the benzyl bromide run with the front of solvent, while your product (hope for you) no.

Try adding plenty of heptane or toluene or a high boiling point polyhaloakane and distill of azeotropically any residual benzyl bromide on a rotavap.

What is your product? It will be difficult to suggest methods of separation unless I know the product and its properties.

Steam distillation was very useful way to remove BnBr or BnCl from reaction mixture in our experiments.

Add Triethylamine, excess benzylbromide will get converted to Benzyltriethyl ammonium bromide which is water soluble. Partition between water and any organic solvent will solve the problem.

Hello

On reaction with benzyl bromide, if precipitate comes then first filter it by using cotton plugged simple funnel then collect filtrate and evaporate solvent. Dissolve your compound in diethyl ether and wash it  with sodium bicarbonate follow by water. concentrate organic layer and purify it by using column chromatography.

I all depends on the scale of the reaction if it is on multigram scale better distillation provided  that the compound of interest has a lower boiling point, smaller scale probably better a chromatography of silicagel benzylbromide it has probably a Rf near 0.9 on 7/3 hexane ethyl acetate eluent and it is easily visualized under UV light of by reaction with iodine voupours ...  if your product it is solid also tritutration on hexanes may do the job .... have a nice day

Hard to say without knowledge of other details on your reaction - especially the product (b.p./m.p., polarity, etc.). However, I like the answer of Danielle Giallombardo - if you need to further purify your product, go for column chromatography. If the product is otherwise pure, than keep it overnight under high vacuum (and eventually combine with mild heating, e.g. to 50 C) and you will get rid of BnBr. If you need it fast, than vacuum destillation would be solution...

Work up the reaction and chromatograph on silica.

I am supporting Sanjiv Tomer, because quaternary salts are highly soluble in water, so you can separate BnBr easily from product

that depends if Et3N does not react with the product. Is it sensible? Can you just do a column?

It is possible to convert benzylbromide in bezylacetate with dry sodium acetate; ester is not so reactive.

It depends mostly on the scale of the reaction and the properties of you desired product.  If your product is a solid, simiply recrystallizing and filtering should remove the BnBr.  On a small scale a scavaging resin would be very easy to perform.  Many different types are available including tertiary amine or thiol based resins that would be likely to remove BnBr.  Even something mild like sodium acetate could also scavenge BnBr.

Use  sodium hydroxide , that will convert you reaction mixture in crystal of sodium bromide.

Work in a well ventilated environment and depending on the scale preferably in a fume hood. Chromatography using 10% EtOAc/Hexane will release the BnBr first followed by increasing the polarity for the product.

Triethyl amine appears reasonable but it might react with one's compound. However, if the stoichiometry of the rxn is known ie what excess of BnBr is present, one can add just sufficient Et3N for "neutralization"

Have you tried either a triphenyl phosphine on polystyrene or sodium thiosulfate solution ?

@Mark Foreman

I haven't tried this procedure, please elaborate

I tend to perform a fast column chromatography for the crude by taking the crude reaction directly to the column without concentration or solvent extraction

addition of excess Et3n and pyridine will be appreciated.......Also you can add PPh3 and slightly heat it, the salt formed will come out of the solution.....

Benzylbromide is very reactive, especially with silveroxyde (Ag2O), you could simply filtered your solution on a pack of silveroxyde supported on silicagel. Good luck.

Benzybromide should react easily with thiourea giving an isothiouronium salt which can be separated by filtration. This salt can be converted afterward into benzymercaptan if needed.

Steam distillation is the very simply method, while irritant BnCl or BnBr from reaction mixture is removed in very clean and non-irritating way, collected in closed system (flask) .

Vacuum evaporation(distillation) at ca. 100 degree is simplest way to remove excess BnBr into a trap, if your product  is stable at higher temperature. 

Before doing workup add  5 -10 ml of methanol .

BnBr can be scavenged by adding potassium thiolate salt.

Chromatrographic  column.... with non polar solvents such as dichloromethane, the benzyl bromide will run immediately out from the column, while your product will run later or with a more polar solvent.