Picolyl chloride hydrochloride → N-(6-methoxy-9-pyridin-2-ylmethyl-2,3,4,9-tetrahydro-1H-carbazol-3-yl)-isobutyramide

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Reaction Steps

Dissolve N-(6-methoxy-2,3,4,9-tetrahydro-1H-carbazol-3-yl)-isobutyramide (200 mg, 0.70 mmol) in anhydrous tetrahydrofuran (6 mL) under nitrogen. Add dropwise potassium bis(trimethylsilyl)amide (3.2 mL, 1.6 mmol, 0.5M in toluene) and stir 30 min. Add slowly 2-(chloromethyl)pyridine hydrochloride (131 mg, 0.80 mmol) in THF/DMF (0.4 mL/1.3 mL) and stir at ambient temperature for 18 h. Quench with saturated ammonium chloride solution (0.5 mL) and partition between ethyl acetate and water. Separate the two phases and wash the aqueous phase with ethyl acetate (2×). Dry the combined organic portions (MgSO4), filter, and concentrate in vacuo to obtain a residue. Purify the material by silica gel chromatography, eluting with 50% ethyl acetate/dichloromethane with a gradient up to 80% ethyl acetate/dichloromethane to obtain 199 mg (75%) of a light yellow solid. MS (ES): m/z 378 (M+1); 1H NMR(DMSO-d6): δ 8.50 (dd, 1H, J=4.8, 0.9 Hz), 7.82 (d, 1H, J=7.5 Hz), 7.65 (dt, 1H, J=7.6, 1.6 Hz), 7.22 (m, 2H), 6.89 (d, 1H, J=2.2 Hz), 6.77 (d, 1H, J=7.9 Hz), 6.63 (dd, 1H, J=8.6, 2.4 Hz), 5.32 (s, 2H), 3.97 (m, 1H), 3.72 (s, 3H), 2.91 (dd, 1H, J=15.0, 5.3 Hz), 2.85-2.76 (m, 1H), 2.74-2.64 (m, 1H), 2.45 (m, 1H), 2.37 (m, 1H), 1.94 (m, 1H), 1.77 (m, 1H), 0.99 (m, 6H).

Provenance & Evidence