Toluene → HCID 178469168, compound

Participants

Reaction Conditions

Reaction Steps

A solution methyl 2-amino-1-methyl-1H-indole-3-carboxylate (426 mg, 2.1 mmol) in toluene (9039 μl) was treated with pTsOH (39.7 mg, 0.209 mmol) and heated to reflux with a Dean-Stark trap. After 4 h, the reaction mixture was cooled to 0° C. and treated with sodium ethoxide (1012 μl, 2.71 mmol) and subsequently heated to reflux (135° C. bath temp). After 18 h, the reaction mixture was cooled to ambient temperature and partitioned between EtOAc and 1M HCl. The organics were washed with brine, dried (MgSO4), filtered and concentrated in vacuo. The residue was purified by ISCO (0-35% EtOAc-hexanes) to afford ethyl 4-hydroxy-2,9-dimethyl-9H-pyrido[2,3-b]indole-3-carboxylate (220 mg, 0.774 mmol, 37.1% yield) as a yellow solid: 1H NMR (400 MHz, CHLOROFORM-d) δ=12.94 (s, 1 H), 8.27 (d, J=7.8 Hz, 1 H), 7.53-7.46 (m, 1 H), 7.45 (s, 1 H), 7.35 (s, 1 H), 4.51 (d, J=7.0 Hz, 2 H), 3.95 (s, 3 H), 2.93 (s, 3 H), 1.50 (s, 3 H); LCMS (m/z) ES+=285 (M+1).

Provenance & Evidence