4-(benzyloxy)-2-(1H-pyrazol-1-yl)pyrimidine-5-carboxylic acid (3-c) was synthesized in a manner outlined in Steps A through Step C of the synthesis of Intermediate 3-e. To a solution of 4-(benzyloxy)-2-(1H-pyrazol-1-yl)pyrimidine-5-carboxylic acid, 3-c, (500 mg, 1.69 mmol) in dry dichloromethane (10 ml) was added dropwise oxalyl chloride (0.29 ml, 3.38 mmol) at 0° C. and a catalytic amount of DMF (3-5 drops). The mixture was stirred at room temperature for 3 hours. Then the mixture was concentrated under vacuum and the residue was dissolved in acetone (10 ml). Et3N (205 mg, 2.03 mmol) was added at 0° C. and the mixture was stirred for 5 mins before sodium azide (988 mg, 15.2 mmol) in water (1 ml) was added. The resulting mixture was stirred at room temperature for 1 h. Subsequently, the mixture was diluted with water and filtered. The solid was washed with water (5-10 ml) and then taken into approximately 20-30 mL of dichloromethane. The organic layer was dried over sodium sulfate and concentrated under vacuum to provide compound 5-a as a solid (130 mg) which was used in Step B without any further purification. (M+H)+=322.
