Lithium Hydroxide → HCID 11478488, compound

Participants

Reaction Steps

Ethyl ester 4.4 (55 mg, 0.094 mmol) was stirred with 1N LiOH (1 ml) in 4 ml of MeOH/THF (1:3) at rt for 24 h, concentrated, and partitioned between Et2O and H2O. The organic phase was extracted with 0.1 N NaOH (2×), and the combined aqueous extracts were acidified with conc. HCl and extracted with EtOAc (3×). The combined organic extracts were washed with H2O, brine, and dried (Na2SO4). Concentration gave a crude product which was purified by semi-preparative HPLC (gradient elution: 70 to 100% CH3CN/H2O+0.1% TFA) to give 4.5,47 mg (90%). HRMS (ESI) calc'd for C33H34ClN2O4 577.2207, found 557.2218 (MH+); 1H NMR (300 MHz, CDCl3) δ 7.83 (d, J=1.1, 1H), 7.39–7.25 (m, 7H), 7.19 (d, J=2.5, 1H), 7.00–6.95 (m, 3H), 6.47 (s, 1H), 4.95 (s, 2H), 4.14–4.05 (m, 1H), 3.88 (s, 3H), 2.24 (s, 3H), 2.10–1.98 (m, 2H), 1.94–1.87 (m, 4H), 1.27–1.22 (m, 4H).

Provenance & Evidence