Butyl nitrite → 6-benzenesulfonyl-1-((R)-1-benzyl-piperidin-3-yl)-1,6-dihydro-1,2,3,5,6-pentaaza-as-indacene

Participants

Reaction Conditions

Reaction Steps

A stirred solution of 1-benzenesulfonyl-N*4*-((R)-1-benzyl-piperidin-3-yl)-1H-pyrrolo[2,3-b]pyridine-4,5-diamine (300 mg, 0.65 mmol) in acetonitrile (6 ml) was treated with copper (II) bromide (174 mg, 0.78 mmol) and n-butyl nitrite (114 μl, 0.97 mmol) and then heated to 70° C. for 2 hours. After cooling, the reaction was quenched by the addition of 1M aqueous HCl solution (ca. 5 ml) and stirred for 5 minutes. The mixture was basified with saturated sodium hydrogen carbonate solution and extracted with ethyl acetate (3×). The combined extracts were washed with brine, dried with sodium sulfate and concentrated under vacuum to leave a brown residue. Purification by column chromatography on silica gel (gradient: 0 to 60% ethyl acetate in cyclohexane) gave 200 mg (65%) of 6-benzenesulfonyl-1-((R)-1-benzyl-piperidin-3-yl)-1,6-dihydro-1,2,3,5,6-pentaaza-as-indacene as a brown residue. LCMS (Method B, ESI): RT=3.38 min, m+H=473.5; 1H NMR (400 MHz, CDCl3) δ: 9.18 (s, 1H), 8.21 (m, 2H), 7.82 (d, 1H), 7.57 (m, 1H), 7.53-7.46 (m, 2H), 7.30 (s, 5H), 6.75 (d, 1H), 4.88 (m, 1H), 3.61 (dd, 2H), 3.25 (m, 1H), 3.03 (m, 1H), 2.57 (m, 1H), 2.39-2.17 (m, 3H), 2.10-1.87 (m, 2H).

Provenance & Evidence