反应详情

Stir a solution of 4-bromo-phenylamine (1 eq), in 1,4-dioxane and cool to approximately 12° C. Slowly-add sulfuric acid (2 eq) and heat at reflux. Add methylvinyl ketone (1.5 eq) dropwise into the refluxing solution. Heat the solution for 1 hour after addition is complete. Evaporate the reaction solution to dryness and dissolve in methylene chloride. Adjust the solution to pH 8 with 1 M sodium carbonate and extract three times with water. Chromatograph the residue on SiO2 (70/30 hexane/ethyl acetate) to obtain the desired subtitled intermediate. MS ES+ m/e =158.2 (M+1).

1. temperatureat reflux
2. temperatureHeat the solution for 1 hour
3. additionafter addition
4. customEvaporate the reaction solution to dryness
5. dissolutiondissolve in methylene chloride
6. extractionextract three times with water