A suspension of trans (1-benzenesulfonyl-5-nitro-1H-pyrrolo[2,3-b]pyridin-4-yl)-(4-methanesulfonyl-cyclohexyl)-amine (585 mg, 1.20 mmol) and ethanol (4 mL, IMS grade) was treated with water (1.3 mL) followed by ammonium chloride (393 mg, 7.30 mmol) and iron powder (274 mg, 4.90 mmol). The mixture was heated to 80° C. for 45 minutes. The resulting solid was isolated and washed repeatedly with ethanol/water. The filtrate was partially concentrated under vacuum and then diluted with DCM and water. The phases were separated and the aqueous phase was extracted with DCM (×2). The combined organic extracts were washed with brine, dried with sodium sulfate and concentrated under vacuum to give 505 mg (92%) of trans 1-benzenesulfonyl-N*4*-(4-methanesulfonyl-cyclohexyl)-1H-pyrrolo[2,3-b]pyridine-4,5-diamine as a pale brown solid that was used without further purification. 1H NMR (400 MHz, DMSO) δ: 8.01 (dd, 2H), 7.70-7.64 (m, 1H), 7.55 (m, 3H), 7.47 (d, 1H), 6.76 (d, 1H), 5.13 (d, 1H), 3.72 (br s, 1H), 3.06 (m, 1H), 2.93 (s, 3H), 2.09 (m, 4H), 1.63 (m, 2H), 1.33 (m, 2H).
