Sodium Carbonate → HCID 89488336, compound

Participants

Reaction Steps

Oven-dried (115° C.) sodium carbonate (18.6 g, 98 mmol, 2.25 eq.) was placed in a 500 mL round-bottom flask. The round-bottom flask was backfilled with Ar and then capped with a rubber septum. A solution of 4-(2,4-dimethoxybenzyl)-3-methylpiperazin-2-one 1.1a (20.6 g, 78 mmol, 1 eq.) in anhydrous DCM (250 mL) was added, followed by triethyloxonium tetrafluoroborate (18.6 g, 98 mmol, 1.25 eq.) in one portion. Thereafter, the reaction mixture was stirred further at RT for 1 h whereupon the reaction mixture was diluted with water (250 mL). The aqueous layer was extracted with DCM (3×150 mL). The organic layers were combined, dried over MgSO4, filtered and concentrated under reduced pressure. The crude compound was then purified on silica gel (EtOAc) to afford the desired product 1a as orange oil. Yield: 13.2 g, 58%. LCMS: P=93%, retention time=1.8 min, (M+H+H2O)+: 311; 1H-NMR (CDCl3): δ 7.23 (d, J=8.8 Hz, 1H), 6.48 (d, J=8.8 Hz, 1H), 6.44 (s, 1H), 4.02 (m, 2H), 3.92 (s, 3H), 3.91 (s, 3H), 3.86 (d, JAB=14.0 Hz, 1H), 3.46 (d, JAB=14.0 Hz, 1H), 3.44 (m, 2H), 3.10 (m, 1H), 2.79 (m, 1H), 2.32 (m, 1H), 1.35 (d, J=6.8 Hz, 3H), 1.24 (t, J=6.0 Hz, 3H).

Provenance & Evidence