Water → 6-{4-[4-(3-pyrrolidin-1-ylpropoxy)phenyl]tetrahydro-2H-pyran-4-yl}-5H-pyrrolo[2,3-b]pyrazine

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Reaction Steps

A solution of 2-methyl-pyrazine (580 μL, 6.4 mmol) in THF (4 mL) was added to 4.7 mL of 1.5M lithium diisopropylamide:THF complex in hexanes at −40° C. and the resulting deep red solution stirred at −40° C. for 0.5 hours. A solution of 4-[4-(3-Pyrrolidin-1-yl-propoxy)-phenyl]-tetrahydro-pyran-4-carbonitrile (1.00 g, 3.2 mmol) in THF (5 mL) was added at −40° C. and the reaction mixture stirred at this temperature for 0.5 hours, then at room temperature for 18 hours. A further 1 equivalent of lithium diisopropylamide complex was then added and the reaction mixture stirred at reflux for 24 hours. The mixture was cooled to room temperature, water (10 mL) added and the mixture concentrated in vacuo. The residue was partitioned between water (60 mL) and DCM (2×60 mL). The organics were combined, dried over sodium sulphate, filtered and concentrated under reduced pressure. The crude product was purified by flash chromatography on silica gel eluting with dichloromethane:methanol:ammonia (95:5:0.5 to 90:10:1, by volume) to provide the title compound (65 mg, 6%) as a brown oil. 1H NMR (400 MHz, CDCl3) δ 1.74-1.80 (m, 6H), 2.00 (m, 2H), 2.42-2.55 (m, 6H), 2.60 (t, 2H), 3.80 (m, 4H), 4.00 (t, 2H), 6.60 (s, 1H), 6.86 (d, 2H), 7.21 (d, 2H), 8.05 (d, 1H), 8.39 (d, 1H). HRMS ESI+ m/z 407.2437 [MH]+.

Provenance & Evidence