In the synthesis of Schiff base from amine and aldehyde condensation, water is produced, so removing it will shitf the equilibrium towards formation of the product. Not removing it will result in poor yield. Usually it is sufficient to add anhydrous MgSO4, activated 4A molecular sieves or using a solvent which is nonmiscible with water. I use the last method (CH2Cl2) with very good results.

thank you...I also want to ask that after formation of the product is it necessary to protect it from aqeous medium?

try once with methanol as solvent 1 to 12 h rt. it may work

Another method is that you can add a suitable solvent like benzene to remove water as azeotropic mixture from the reaction vessel. For that you have to use dean-stark apparatus. Its a very easy process to remove water from reaction mixture.