反应详情

温度

0 °C

A solution of 40.0 g (0.137 mole) of phenyl 4-cyano-2,2,4-trichlorobutyrate and 190 ml of anhydrous sulfolane in a glass lined pressure reactor was cooled to 0° C. in an ice-water bath, and charged with dry HCl gas (28 g) at 5° C. by passing dry HCl gas therethrough. The reactor was closed and the reaction mixture heated with stirring at 125° C. for 5 hours. After cooling to ambient temperature, the HCl gas was vented off and a clear brown solution was obtained. GLC analysis of the resulting solution indicated a yield of 78% (±1%) of 3,5,6-trichloropyridin-2-ol. The solution was poured into water and extracted with several portions of methyl t-butyl ether. The combined extract was washed with water and then stirred for 1 hour with 150 ml of aqueous 13% sodium carbonate solution. A white solid formed in the aqueous phase and was filtered off, washed with methyl t-butyl ether and dried to give 23.0 g of 3,5,6-trichloropyridin-2-ol sodium salt. By acidifying the above sodium salt with dilute aqueous HCl, it was quantitatively converted into a white powder consisting of 3,5,6-trichloropyridin-2-ol, m.p. 170°-171° C. This substance was found to be identical in all respects with an authentic sample of the material.

1. customThe reactor was closed
2. temperaturethe reaction mixture heated
3. temperatureAfter cooling to ambient temperature
4. customa clear brown solution was obtained