反应详情

9.5 g of 4-(5-amino-2-pyridyl)-2,2-dimethyl-2H-1-benzopyran-6-carbonitrile were dissolved in 150 ml of acetic acid and 100 ml of water. 3.16 g of sodium nitrite in 10 ml of water were added at such a rate as to keep the temperature below 5° C. After 15 minutes 23 g of potassium iodide in 20 ml of water were added and the mixture was stirred at room temperature for 1 hour. The mixture was then poured into 1 l of 2M sodium hydroxide solution and extracted with ethyl acetate. The organic extract was dried over sodium sulphate and evaporated. The residue was chromatographed on silica gel using ethyl acetate/petroleum ether (1:4) for the elution to give 4.78 g of 4-(5-iodo-2-pyridyl)-2,2-dimethyl-2H-1-benzopyran-6-carbonitrile which was used without further purification.

1. customthe temperature below 5° C
2. extractionextracted with ethyl acetate
3. extractionThe organic extract
4. dry with materialwas dried over sodium sulphate
5. customevaporated
6. customThe residue was chromatographed on silica gel
7. washfor the elution