Cesium carbonate → HCID 58730940, compound

Participants

Reaction Conditions

Reaction Steps

To the crude pinacol ester 44 (310 mg, 1.27 mmol) in dry toluene (25 mL) was sequentially added cesium carbonate (2.07 g, 6.35 mmol), tetrakis(triphenylphosphine)palladium(0) (73 mg, 0.06 mmol) and 3,4-dimethoxybenzoyl chloride (510 mg, 2.54 mmol). The mixture was heated at 100° C. in the dark. After 28 h a further portion of tetrakis(triphenylphosphine)palladium(0) (90 mg, 0.08 mmol) was added. Following another 22 h the mixture was allowed to cool to ambient temperature and diluted with EtOAc and water and partitioned. The organic layer was washed with saturated sodium hydrogen carbonate, saturated brine, dried (MgSO4), filtered and concentrated. The crude residue was purified by preparative LCMS (column LUNA 10μ C18(2) 00G-4253-V0 250×50 mm) using water—acetonitrile (0.1% AcOH) as eluent (in gradient; flow 80 mL/min) to afford ketone 45 [12.6 mg, 3.6% (2 steps)] as a white solid. 1H NMR (400 MHz; CDCl3) δ 3.99 (s, 3H), 4.00 (s, 3H), 6.54 (dd, J=2.0 and 3.5 Hz, 1H), 6.98 (d, J=8.5 Hz, 1H), 7.38 (dd, J=2.5 and 3.5 Hz, 1H), 7.71 (d, J=2.0 Hz, 1H), 7.81 (dd, J=0.7 and 2.5 Hz, 1H), 7.93 (dd, J=2.0 and 8.5 Hz, 1H), 8.22 (d, J=2.5 Hz, 1H) and 8.90 (brs, NH).

Provenance & Evidence