反应详情

A mixture of 3-amino-5-(pyridin-4-yl)thiophene-2-carboxylic acid (0.220 g, 1.00 mmol), ammonium chloride (0.267 g, 5.00 mmol), triethylamine (0.70 mL, 5.0 mmol) and DMF (3.0 mL) was stirred for 5 min. 1-Hydroxybenzotriazole (0.204 g, 1.50 mmol) and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (0.286 g, 1.50 mmol) were added and stirring was continued overnight. Then, DMF (2 mL), ammonium chloride (0.267 g, 5.00 mmol), triethylamine (0.70 mL, 5.0 mmol), 1-hydroxybenzotriazole (0.204 g, 1.50 mmol) and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (0.286 g, 1.50 mmol) were added again. After 6 h, the mixture was poured into aqueous sodium hydrogen carbonate (50 mL). Extraction with ethyl acetate-tetrahydrofuran (2:1, 2×30 mL), drying over magnesium sulfate, filtration and concentration at reduced pressure gave the title compound (0.185 g, 84%) as a yellow solid:

1. stirringstirring
2. waitwas continued overnight
3. waitAfter 6 h
4. extractionExtraction with ethyl acetate-tetrahydrofuran (2:1, 2×30 mL)
5. dry with materialdrying over magnesium sulfate, filtration and concentration at reduced pressure