Dear Avtar Singh,

Which type of chloride do you have?. If the chloride is an alkyl chloride, please, find below a link to an artlicle on: Selective Reductions. XI. The Reaction of Sodium Borohydride with Alkyl Halides under Solvolytic Conditions. Borohydride as a Convenient Trap for Carbonium Ions1,2

by: Harold M. Bell, Herbert C. Brown

J. Am. Chem. Soc., 1966, 88 (7), pp 1473–1477

https://www.google.com.eg/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwi8oYmkqcvOAhUF7hoKHcnMCeAQFggfMAA&url=http%3A%2F%2Fpubs.acs.org%2Fdoi%2Fabs%2F10.1021%2Fja00959a028&usg=AFQjCNH55_dj-Jtqywi3llIIUdRd0G2U-A

Best wishes

Dear Avtar Singh,

Please, find in attach the paper entitled: Selective Reductions. XI. The Reaction of Sodium

Borohydride with Alkyl Halides under Solvolytic Conditions.

Borohydride as a Convenient Trap for Carbonium Ions1i2

Harold M. BelI3n4 and Herbert C. Brown

I hope to be useful for you.

Good luck

Talaat, I think you are misunderstanding Avtar - he is not looking to reduce an organochloride, he wants to replace a chloride ion with borohydride.  

Avtar, it appears that it is fairly straightforward.  http://onlinelibrary.wiley.com/doi/10.1002/anie.200905359/full

I would also day, that under inert and dry conditions the exchange should proceed smoothly, the only question is how pure the product is, in the publication there is only NMR and IR, which is quite useless for Cl determination

The experimental details are freely available (see attached file.)

I would think that the insolubility of NaCl in THF and ionic liquids would drive almost all of the chloride out of solution.  You could treat the product with a second batch of NaBH4 in THF if you needed a very low level of chloride, and use centrifugation to remove NaCl particles that aren't caught by filtration.

Actually the solubility of NaCl in ILs is suprisingly high and can reach 5% (depending on the IL)

It seems that I missunderstood the question asked by Avtar well. The question is not clear enough. The paper provided by  Joseph S Merola  and James Demers looks useful.

If that's the case with the ILs under consideration, then an analysis for chloride will be necessary.  I have used the Mohr titration for samples as low as 20 ppm.

Potassium borohydride might give better results, as KCl should be less soluble in the IL.

http://pubs.acs.org/doi/abs/10.1021/ie401282y

I agree with Demers.

Including, potassium borohydride is cheaper and less hygroscopic than the sodium salt.

I suggest you to try a solution of potassium borohydride in anhydrous or dried THF or dioxan. Then, after the reaction, centrifugue to remove the precipitated potassium chloride.

also, make a search in the literature, because... your ionic liquid is acidic or alcaline? is oxidizer? Remenber that borohydrides are reductors and unstable in alkaline solutions (i'm not certain about their reactions with acids).

Dissolve your IL in dimethoxyethane (monoglyme), add an excess of  NaBH4, stir for 1 -2 days, filter off the precipitate, remove DME in vacuum. Essential: NaBH4 before use must be recrystallized from dyglime or DME/NH3 (Russian J. of Applied Chemistry, 1992, v. 65 number 11) and dried in vacuum. The purity must be > 99% for active hydrogen determined volumetrically by adding acidic water solution to a sample of NaBH4. THF or dioxane for the exchange reaction are of no use, because neither NaBH4 nor KBH4 are not soluble in them. Also you can try an equivalent quantity of Ca(BH4)2  in THF. CaCl2 formed is not soluble in THF but Ca(BH4)2 is very soluble in it. So, avoid the excess of Ca(BH4)2!

Dear sir, thanks for your response. Can you please provide me the paper that you have mentioned (Russian J. of Applied Chemistry, 1992, v. 65 number 11), in my institute I 'm not able to access the same.

I have it only in Russian. If it will suit you I'll send it Monday. As an example of the exchange reaction I send you my paper on the synthesis of NaV(BH4)4 For other examples you can browse through my works on the Researchgate.

Thank you so much sir