Hydrochloric Acid → HCID 17870033、化合物

Compound 2 was synthesized from Compound 1 as follows. To a solution of Compound 1 (306 mg, 1.32 mmol) dissolved in dioxane (18 mL) was added LiOH (2 M aqueous solution, 992 μL, 1.98 mmol, 1.5 equiv). After 1 h, hydrochloric acid (1 M aqueous solution) was added dropwise to give a solution with pH=5. The solution was concentrated and the resulting pale brown oil was dissolved in ethyl acetate (20 mL) and washed with acetic acid (5% aqueous solution, 10 mL), water (10 mL), and brine (10 mL). The organic layer was dried over sodium sulfate, filtered, and concentrated to a pale brown oil. Purification by silica gel chromatography (5-50% ethyl acetate in hexanes with 0.1% acetic acid) yielded the product as a pale yellow solid (290 mg, 1.34 mmol, quantitative). 1H NMR (400 MHz, CDCl3) δ 9.89 (s, 1H), 7.76 (dt, J=8.1, 0.9 Hz, 1H), 7.53 (dd, J=8.6, 0.9 Hz, 1H), 7.48-7.43 (m, 1H), 7.33 (d, J=0.8 Hz, 1H), 7.21 (ddd, J=8.0, 6.9, 1.0 Hz, 1H), 4.85 (t, J=7.2 Hz, 2H), 2.91 (t, J=7.2 Hz, 2H). 13C NMR (101 MHz, CDCl3) δ 182.65, 176.96, 140.12, 135.02, 127.33, 126.42, 123.53, 121.27, 118.76, 110.55, 40.19, 34.82. HRMS (ESI) calcd for C12H10NO3 [M−H]−: 216.0666. found: 216.0665.