Pyridine → HCID 135507203, compound

Participants

Reaction Steps

7-(4-Fluoro-benzyl)-5,9-dihydroxy-pyrrolo [3,4-g]quinoxaline-6,8-dione 242 (1 g, 2.95 mmol, 1 equiv.) was dissolved in DMF (30 ml, 0.1 M) and pyridine (477 μL, 5.89 mmol, 2 equiv.) before ethyl chloroformate was added (237 μL, 2.95 mmol, 1 equiv.). The reaction was stirred for 16 hours before being quenched with HCl (30 ml, 1 N) and extracted with ethyl acetate (2×30 mL). The organic layer washed several times with water (4×30 mL), saturated NaHCO3 (50 mL), brine solution (50 mL). It was dried over Na2SO4, filtered and concentrated in vacuo. Recrystallization was carried out in ethyl acetate and Hexanes to yield carbonic acid ethyl ester 7-(4-fluoro-benzyl)-9-hydroxy-6,8-dioxo-7,8-dihydro-6H-pyrrolo[3,4-g]quinoxalin-5-yl ester 243 as a light brown solid (98%, 1.20 g, 2.89 mmol). 1H NMR (300 MHz) CDCl3 δ 9.09 (d, J=6 Hz, 1 H), 8.97 (d, J=6 Hz, 1 H), 8.65 (bs, 1 H), 7.46 (d, J=4.8 Hz, 2 H), 7.03 (d, J=4.8 Hz, 2 H), 4.85 (s, 2 H), 4.04 (q, J=2.8 Hz, 2 H), 1.43 (q, J=2.8 Hz, 3 H). MS: 412.6 (M+1).

Provenance & Evidence