反应详情

3-Amino-5-nitroindazole-1-carboxylic acid tert-butyl ester (600 mg, 2 mmol) was dissolved in dry pyridine (15 mL) under nitrogen. The solution was cooled on an ice bath and 3-chlorobenzoyl chloride (0.3 mL, 2 mmol) added. After 6 hours, the mixture was diluted with EtOAc, washed with 1M hydrochloric acid solution (×3) and brine then dried over magnesium sulfate and concentrated to a solid. Purification by column chromatography (silica, 7:3 petrol)-EtOAc) afforded the title compound as a solid (300 mg, 39%); 1H NMR (400 MHz, CDCl3) 1.77 (9H, s), 7.52 (1H, t), 7.62 (1H, d), 7.90 (1H, d), 8.07 (1H, m), 8.32 (1H, d), 8.45 (1H, d), 9.22 (1H, brs), 9.32 (1H, s); MS (ES+) m/e=417.

1. temperatureThe solution was cooled on an ice bath
2. washwashed with 1M hydrochloric acid solution (×3) and brine
3. dry with materialthen dried over magnesium sulfate
4. concentrationconcentrated to a solid
5. customPurification by column chromatography (silica, 7:3 petrol)-EtOAc)