To a solution of 6-aminonicotinic acid (130 mg, 0.941 mmol) and 4-benzyloxy-benzylamine (201 mg, 0.941 mmol) described in Preparation Example 1 in N,N-dimethylformamide (5 mL), was added benzotriazol-1-yl-tris(dimethylamino)phosphonium hexafluorophosphate (624 mg, 1.41 mmol) and triethylamine (394 μl, 2.82 mmol), and the solution was stirred for 40 minutes at 80° C. Water and ethyl acetate were added to the reaction solution, which was then partitioned, and the organic layer was washed twice with water. The solvent was evaporated in vacuo, ethyl acetate was added to the residue, a white insoluble matter was collected by filtration, and 6-amino-N-(4-benzyloxy-benzyl)-nicotinamide (202 mg, 0.606 mmol, 64%) was obtained.
