Trifluoroacetic acid → Trifluoroacetic acid

Participants

Reaction Steps

To a solution of 277 dissolved in dichloromethane (2 mL) was added trifluoroacetic acid (200 μl) and triethylsilane (400 μl). The reaction mixture was stirred at room temperature for ½ hours under an inert atmosphere then concentrated in vacuo. The residue was redissolved in DMSO (1 mL) and purified by prep-HPLC to afford 3-[7-(4-fluoro-benzyl)-9-hydroxy-8-oxo-7,8-dihydro-6H-pyrrolo[3,4-g]quinolin-5-yl]-benzoic acid ethyl ester 278, TFA salt, (25 mg, 0.003 mmol, 44% in two steps) as a yellow solid: 1H NMR (CDCl3) δ 9.0 (d, 1H), 8.2 (d, 1H), 8.0 (s, 1H), 7.7 (m, 1H), 7.6 (dd, 1H), 7.5 (dd, 2H), 7.0 (m, 2H), 7.1 (t, 2H), 4.7 (dd, 2H), 4.4(q, 2H), 4.3 (dd, 2H), 1.4 (t, 3H); MS: 457 (M+1). HPLC conditions: mobile phase A was 0.1% TFA in water, mobile phase b was 0.1% TFA in CH3CN; gradient from 5% to 60% B in 20 min; flow rate was 20 mL/min; column was Phenomenex, luna 5μ, C18 (2), 150 mm×21.1 mm.

Provenance & Evidence