The reaction of ketones with primary amines or ammonia forms imine derivatives, also known as Schiff bases (compounds having a C=N function). Water is eliminated in the reaction, which is acid-catalyzed and reversible. The pH for reactions which form imine compounds must be carefully controlled. The rate at which these imine compounds are formed is generally greatest near a pH of 5, and drops at higher and lower pH's.

http://pubs.acs.org/doi/abs/10.1021/jo982059i

 Thanks alot Purohit but can you write the detailed steps and the time of reaction needed

I am familiar with two distinctly different methods to prepare imines. My favorite (the easiest) is to mix equimolar quantities of carbonyl with amine and heat in toluene to reflux with a Dean Stark trap. When the Dean Stark holds the theoretical water liberated in the reaction, you're finished! Simply remove the rest of the toluene on rotavap. However, most imines do not form so easily (especially from hindered ketones), and require more powerful desiccants such as MgSO4 or Ti(OiPr)4. These protocol require careful workup, and usually risk hydrolysis of your newly formed imine.

The other "method" utilizes a sulfinic ester intermediate, and though requires more chemicals, the procedure is straightforward. I used the following procedure to prepare an oxaziridine from the intermediate imine, though it may only work with sulfonamides, I haven't explored a huge substrate scope, the internet will have more to say. Enjoy!

p-Toluenesulfonamide (5.14 g, 30 mmol) and sodium benzenesulfinate (5.42 g, 33 mmol) were dissolved in a 1:1 mixture of formic acid and water (90 mL). The corresponding ketone (30 mmol) was added and the mixture was stirred overnight at room temperature. The resulting white precipitate was filtered off, washed with water (20 mL) and pentane (15 mL) and dissolved in CH2Cl2 (200 mL). Saturated aqueous NaHCO3 (140 mL) was added and the mixture was stirred at room temperature for 2 h. The organic phase was separated and the aqueous phase was extracted with CH2Cl2 (50 mL). The combined organic layers were dried over MgSO4, filtered and concentrated to yield the corresponding crude imine. These products were used in the next step without further purification.

THanks Alot Brennan this is very interisting details about this synthesis process