1,4-Dibromobutane → HCID 136262717, compound

Participants

Reaction Conditions

Reaction Steps

A 15 ml reaction vial is flushed with nitrogen and charged with dry THF (2.5 ml), magnesium turnings (55.5 mg, 2.28 mmol) and cerium(III) chloride (20.5 mg, 0.084 mmol). The suspension is cooled to 0° C., 1,4-dibromobutane (157 μl, 1.33 mmol) is added. The suspension is allowed to reach room temperature, stirred for 30 minutes at this temperature and again cooled to 0° C. Then, a solution of 4-(4-oxo-3,4-dihydro-pyrrolo[2,1-f][1,2,4]triazin-2-yl)-benzoic acid methyl ester (113 mg, 0.42 mmol) in THF (1 ml) is added dropwise. The reaction mixture is stirred for 30 minutes at room temperature. The reaction mixture is quenched with saturated ammonium chloride solution and partitioned between ethyl acetate and water. The organic phase is dried over sodium sulfate and evaporated. The residue is chromatographed on a silica gel column with cyclohexane/ethyl acetate as eluent to afford 2-[4-(1-hydroxy-cyclopentyl)-phenyl]-3H-pyrrolo[2,1-f][1,2,4]triazin-4-one as white solid; HPLC/MS 1.75 (C), [M+H] 296; 1H NMR (400 MHz, DMSO-d6) δ [ppm] 11.92 (s, 1H), 7.98-7.89 (m, 2H), 7.67 (dd, J=2.7, 1.7 Hz, 1H), 7.65-7.59 (m, 2H), 6.94 (dd, J=4.3, 1.7 Hz, 1H), 6.60 (dd, J=4.3, 2.6 Hz, 1H), 4.94 (s, 1H), 1.95-1.85 (m, 6H), 1.83-1.74 (m, 2H).

Provenance & Evidence