5-Iodo-7-triisopropylsilanyl-7H-pyrrolo[2,3-d]pyrimidine (38, 0.160 g, 0.4 mmol) was dissolved in 0.7 mL of tetrahydrofuran under an atmosphere of nitrogen. The reaction was cooled to −20° C. and isopropylmagnesium chloride (0.24 mL, 2.0 M in tetrahydrofuran, 0.48 mmol) was added and the reaction was stirred and allowed to come to 0° C. The reaction was cooled to −20° C. and (4-chloro-benzyl)-(5-formyl-pyridin-2-yl)-carbamic acid tert-butyl ester (13, 0.110 g, 0.32 mmol) in 2.0 mL of tetrahydrofuran was added to the reaction mixture. The reaction was stirred, allowing to come to 0° C., then poured into aqueous saturated sodium bicarbonate and extracted with ethyl acetate. The organic layer was washed with brine, dried over anhydrous sodium sulfate, filtered and the filtrate concentrated under vacuum. The resulting material was purified by silica gel column chromatography eluting with a gradient of 10-80% ethyl acetate in hexanes. Appropriate fractions were combined and concentrated under vacuum to provide the desired compound (43, 0.103 g, 52%). MS (ESI) [M+H+]+=622.94.
