Ammonium Chloride → 1-benzenesulfonyl-N*4*-((R)-1-benzyl-piperidin-3-yl)-1H-pyrrolo[2,3-b]pyridine-4,5-diamine

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Reaction Steps

A mixture of (1-benzenesulfonyl-5-nitro-1H-pyrrolo[2,3-b]pyridin-4-yl)-((R)-1-benzyl-piperidin-3-yl)amine (about 0.77 mmol), iron powder (129 mg, 2.31 mmol) and ammonium chloride (206 mg, 3.85 mmol) in ethanol/water (8 ml, 3:1) was heated to reflux for 4 hours. After cooling the mixture was filtered through CELITE®, thoroughly washing the filter cake with ethanol. The filtrate and washings were combined and concentrated under vacuum. The resulting residue was partitioned between ethyl acetate and water, and the organic layer dried with sodium sulfate and concentrated under vacuum. Purification by column chromatography on silica gel (gradient: 0 to 10% methanol in DCM) gave a residue, which was purified by column chromatography on silica gel (gradient: 0 to 5% methanol in ethyl acetate) affording 303 mg (84%) of 1-benzenesulfonyl-N*4*-((R)-1-benzyl-piperidin-3-yl)-1H-pyrrolo[2,3-b]pyridine-4,5-diamine. LCMS (Method B, ESI): RT=2.48-2.68 min, m+H=462.6; 1H NMR (400 MHz, CDCl3) δ: 8.12-8.08 (m, 2H), 7.79 (s, 1H), 7.55-7.49 (m, 1H), 7.46-7.38 (m, 3H), 7.37-7.22 (m, 5H), 6.47 (s, 1H), 5.32-5.26 (br m, 1H), 4.00-3.87 (br m, 1H), 3.58-3.46 (br m, 2H), 2.94-2.28 (br m, 6H), 1.82-1.67 (br m, 2H).

Provenance & Evidence