To a solution of the product of step 4 (6.5 g, 0.0171 moles) in DMF (40 mL), (tetrahydro-2H-pyran-4-yl)methanamine hydrochloride (2.6 gm, 0.0171 moles), HOBT (2.31 gm, 0.0171 moles), EDC.HCl (4.24 gm, 0.0222 moles) and N-ethyl morpholine (5.9 gm, 0.0513 moles) were added and reaction mixture was srirred at 25° C. for 5 hours under nitrogen atmosphere. The reaction mixture was poured into ice cold water and extracted with ethyl acetate. The combined ethyl acetate extract was washed with water & brine, dried over sodium sulphate and evapourated under reduced pressure. The crude product was purified by coloumn chromatography using 1% MeOH in chloroform as eluent to yield 1.22 g (15%) of product as white solid.
