Ethanesulfonylchloride, 2-chloro- → Ethyl 4-{3-[(ethenylsulfonyl)amino]phenyl}-7H-pyrrolo[2,3-d]pyrimidine-5-carboxylate

To ethyl 4-(3-aminophenyl)-7H-pyrrolo[2,3-d]pyrimidine-5-carboxylate (60 mg, 0.21 mmol) was added DCM (1.1 mL) and DIPEA (45 μL, 0.26 mmol) at 0° C. Then 2-chloroethanesulfonyl chloride (68 mg, 0.42 mmol) was added and the reaction was stirred vigorously for 15 hours before being quenched by pouring into a separatory funnel containing aqueous sodium hydrogen carbonate (20%). The aqueous layer was then extracted with ethyl acetate (×3) and the organic layers were combined, dried with Na2SO4, filtered, and concentrated in vacuo. The crude product was then purified using a silica column, eluting with DCM with a 10-80% of a 2% methanol/EtOAc modifying co-solvents. The product was collected and concentrated in vacuo to afford the desired product as a yellow solid. LRMS (ESI) calc'd for C17H17N4O4S [M+H]+: 373, found 373. 1H NMR (600 MHz, CDCl3) δ 10.74 (bs, 1H), 9.04 (s, 1H), 8.12 (s, 1H), 7.38-7.54 (m, 5H), 6.61 (dd, 1H, J=17.4, 10.8 Hz), 6.33 (d, 1H, J=16.2 Hz), 5.96 (d, 1H, J=10.2 Hz), 4.04 (q, 2H, J=7.2 Hz), 1.01 (t, 3H, J=7.2 Hz).