反应详情

A red solution of 34 g (79.4 mmol) of the benzophenone prepared in step A in 200 ml acetic acid is treated with 6.2 g (95 mmol) sodium cyanate under vigorous stirring which is continued overnight. The mixture is diluted with water and extracted with ethyl acetate. Concentration after washing with bicarbonate solution yields several crops of product. While the initial batches are yellow and pure, the subsequent ones are orange and have to be purified by flash chromatography. Combined yield: 25.9 g (72%). m.p. 167-168° C.

1. extractionextracted with ethyl acetate
2. concentrationConcentration
3. washafter washing with bicarbonate solution
4. customyields several crops of product
5. customto be purified by flash chromatography