反应详情

A solution of sodium hypobromite prepared by dissolving bromine (1.0 mole) in a solution of sodium hydroxide (3.5 mole) in water (700 ml) at 0° C. was added to a well stirred solution of 4-n-propylacetophenone (0.2 mole), prepared in step A1, in dioxan (500 ml). Throughout the addition and for 0.25 hours afterwards the temperature was maintained at 35°-45° C. The excess of sodium hypobromite wad destroyed by adding a solution of sodium metabisulphite. Water (3.5 L) was added and bromoform distilled from the reation mixture. On cooling, the solution was acidified with concentrated hydrochloric acid and the precipitated product filtered off and washed with water. The product was crystallised from ethanol/water to yield white crystals mpt 141.2° C.

1. additionwas added to a well
2. additionThroughout the addition
3. temperaturefor 0.25 hours afterwards the temperature was maintained at 35°-45° C
4. customThe excess of sodium hypobromite wad destroyed
5. additionby adding a solution of sodium metabisulphite
6. additionWater (3.5 L) was added
7. distillationbromoform distilled from the reation mixture
8. temperatureOn cooling
9. filtrationthe precipitated product filtered off
10. washwashed with water
11. customThe product was crystallised from ethanol/water