HCID 86752885, compound → HCID 86752884, compound

Participants

Reaction Steps

To a 500 mL flask equipped with a nitrogen inlet and a magnetic stir was added 20 g (0.033) dibenzyl ether 2 from Example 1B and 330 mL (0.3M) trifluoroacetic acid (Aldrich). The dark blue mixture was allowed to stir at room temperature for 48 hours after which all of 2 had been consumed as measured by LC in addition to one minor impurity (monobenzyl ether). The reaction was quenched with 1 L ice water and the bisphenol was extracted into 300 mL Et2O. The organic layer was washed 2×100 mL H2O 5×100 mL aq. sodium bicarbonate (sat.) and 2×100 mL H2O dried over MgSO4, filtered and reduced in vacuo giving ca. 20 g crude 3 as a dark red powder (ca. 60 percent by LC). All attempts at recrystallization failed and the two components were separated by high pressure flash chromatography (Biotage) on silica with CH3 CN/CH2Cl2 (20/80 percent) TLC ΔRf =0.119) giving 3.2 g of BHPD as a red powder (m.p. 237°-240° C.) in 25 percent isolated yield (99+ percent by LC). It had the following spectral properties. 1H NMR (250 MHz, DMSO-d6): δ6.7 (d,2H), 6.82 (d,4H), 7.1 (d,4H), 7.75 (d,2H), 7.91 (d, 2H), 8.32 (d,2H), 9.55 (d, 2H, OH). 13C NMR (63 MHz, DMSO-d6): δ115.5, 116.5, 122.6, 124.9, 125.5, 128.4, 136.6, 144.3, 147.4, 153.1, 155.6, 156.9. GCMS (EI) m/z calcd (found) for C24H18N4O4 =426 (426 w/276 at 100 percent).

Provenance & Evidence