反应详情

温度

0 °C

In a dry flask 5-amino-indazole-1-carboxylic acid t-butyl ester (1.4 g, 6.0 mmol) was dissolved in tetrahydrofuran (20 mL) and triethylamine (1.0 g, 9.9 mmol) were added and the reaction mixture cooled to 0° C. Phenyl chloroformate (1.0 g, 6.4 mmol) was added dropwise and the mixture was stirred an additional 15 minutes after the addition was complete. The reaction mixture was diluted with ethyl acetate, washed with water, and concentrated in vacuo. The crude material was purified by flash chromatography with 35% ethyl acetate in hexanes to give a white solid (1.9 g, 90%). 1H NMR (300 MHz, CDCl3), δ: 8.14 (d, J=10, 1H), 8.12 (s, 1H), 8.02 (bs, 1H), 7.40 (m, 3H), 7.24 (m, 4H), 1.73 (s, 9H).

1. additionafter the addition
2. washwashed with water
3. concentrationconcentrated in vacuo
4. customThe crude material was purified by flash chromatography with 35% ethyl acetate in hexanes