反应详情

A mixture of ethyl 5-amino-α,α-dimethyl-1,2-benzisothiazole-3-acetate (0.546 g, 2.06 mmol) and 2-dimethylamino-4-(trifluoromethyl)-6H-1,3-oxazin-6-one (0.430 g, 2.06 mmol) in acetic acid is refluxed for 4.5 hours, concentrated in vacuo, and diluted with saturated sodium hydrogen carbonate solution. The resultant aqueous mixture is extracted with methylene chloride. The combined organic extracts are washed with water, dried over anhydrous sodium sulfate, and concentrated in vacuo to obtain a brown foam. A solution of the foam in N,N-dimethylformamide is treated with potassium carbonate (0.312 g, 2.25 mmol), stirred for one hour, treated with iodomethane (0.420 mL, 6.70 mmol), stirred overnight at room temperature, and poured into an ice-water mixture containing 20 mL of concentrated hydrochloric acid. The resultant aqueous mixture is extracted with methylene chloride. The combined organic extracts are washed sequentially with 10% hydrochloric acid, water, saturated sodium hydrogen carbonate solution and water, dried over anhydrous sodium sulfate and concentrated in vacuo to obtain a brown oil. Column chromatography of the oil using silica gel and a 33% ethyl acetate in methylene chloride solution affords a pink foam which is recrystallized from ethanol to give the title product as pink crystals, mp 164-167° C.

1. temperatureis refluxed for 4.5 hours
2. concentrationconcentrated in vacuo
3. additiondiluted with saturated sodium hydrogen carbonate solution
4. extractionThe resultant aqueous mixture is extracted with methylene chloride
5. washThe combined organic extracts are washed with water
6. dry with materialdried over anhydrous sodium sulfate
7. concentrationconcentrated in vacuo
8. customto obtain a brown foam
9. stirringstirred overnight at room temperature
10. extractionThe resultant aqueous mixture is extracted with methylene chloride
11. washThe combined organic extracts are washed sequentially with 10% hydrochloric acid, water, saturated sodium hydrogen carbonate solution and water
12. dry with materialdried over anhydrous sodium sulfate
13. concentrationconcentrated in vacuo
14. customto obtain a brown oil
15. customis recrystallized from ethanol