Methanol → HCID 178496862, compound

Participants

Reaction Steps

To a suspension of quindoline-11-carboxylic acid (2.3 g, 8.77 mmol) from Example 1 in MeOH (50 mL) was added concentrated H2SO4 (1.5 ml, 28 mmol). The resulting solution was refluxed for 8 hours, cooled, and partitioned between benzene (100 mL) and water (50 mL). After adjusting the pH to 9 with a saturated solution of K2CO3, the benzene layer was separated, washed with water, dried and concentrated. Purification by LPLC (EtOAc-hexane 1:3) gave 0.28 g of the title compound as greenish-yellow crystals (from hexane), mp 152-153.5° C. [lit 152.5-154° C. (Degutis, Y. A.; Ezyarskaite, A. B. Khim. Geterotsik. Soedin. 1986, 1375)]; 1H NMR (CDCl3) δ 9.75 (s, 1H), 9.09 (d, J=6.4, 1H), 8.51 (d, J=8.0, 1H), 8.38 (d, J=7.2, 1H), 7.72-7.62 (m, 3H), 7.49 (d, J=8.0, 1H), 7.38 (t, J=8.0, 1H); 13C NMR (CDCl3) δ 168.19, 147.81, 144.43, 143.56, 133.91, 130.50, 130.27, 127.40, 126.18, 125.05, 123.66, 122.23, 121.65, 121.06, 111.19, 109.21, 52.54; MS (EI, m/z) 276 (M+). Acidification of the water layer with HCl gave 1.8 g (78.3%) of recovered starting material.

Provenance & Evidence