Diisopropylethylamine → (1-Benzenesulfonyl-5-nitro-1H-pyrrolo[2,3-b]pyridin-4-yl)-(S)-tetrahydro-pyran-3-yl-amine

(S)-(Tetrahydro-pyran-3-yl)amine hydrochloride (40.7 g, 296.09 mmol) and N,N-diisopropylethylamine (130 mL, 760 mmol) were added to a solution of 1-Benzenesulfonyl-4-chloro-5-nitro-1H-pyrrolo[2,3-b]pyridine (100.0 g, 296.09 mmol) in ispropanol (1.0 L). The mixture was stirred at an internal temperature of 75° C. for 4 hours. The mixture was then allowed to cool down slowly and left still overnight. The resulting solid was collected by filtration and washed with cold isopropanol. The solid was then dried in a vacuum oven for 24 h to afford 114.0 g (95.7%) of (1-Benzenesulfonyl-5-nitro-1H-pyrrolo[2,3-b]pyridin-4-yl)-(S)-tetrahydro-pyran-3-yl-amine as a yellow solid. LCMS (Method D, ESI): RT=1.63 min, m+H=403.2; 1H NMR (400 MHz, DMSO) δ 9.21 (d, J=8.1 Hz, 1H), 8.92 (s, 1H), 8.13 (d, J=7.8 Hz, 2H), 7.77 (dt, J=25.1, 10.9 Hz, 2H), 7.66 (t, J=7.7 Hz, 2H), 7.02 (d, J=4.1 Hz, 1H), 4.28 (s, 1H), 3.88-3.65 (m, 3H), 3.56 (t, J=8.9 Hz, 1H), 2.00 (t, J=11.5 Hz, 1H), 1.93-1.63 (m, 2H), 1.53 (dd, J=9.4, 4.2 Hz, 1H), 1.28 (t, J=6.9 Hz, 1H).