反应详情

Treat a stirred mixture of 2-methoxy-5-(5-thioxo-1,5-dihydro-[1,2,4]triazol-4-yl)-benzoic acid methyl ester (3.80 g, 14.38 mmol), potassium carbonate (2.19 g, 15.8 mmol) and anhydrous acetone (60 mL) with methyl iodide (1.07 mL, 17.25 mmol) added dropwise via syringe. Reflux the stirred mixture for 2.5 hours, cool, filter and wash the filter cake twice with acetone. Combine the acetone phases, concentrate in vacuo, dissolve the residue in ethyl acetate and wash with NaHCO3 solution. Extract the combined aqueous phases three times with ethyl acetate. Combine the ethyl acetate phases, wash with saturated NaHCO3 and brine, dry (MgSO4), filter and concentrate in vacuo to afford an oil. Purify the oil by flash chromatography (silica gel, 5.5×15.2 cm) eluting with ethyl acetate and then with 5% methanol in dichloromethane after elution of the starting material. Concentrate the appropriate fractions to afford 2.89 g of 2-methoxy-5-(3-methylsulfanyl-[1,2,4]triazol-4-yl)-benzoic acid methyl ester as a colorless solid.

1. additionTreat
2. additionadded dropwise via syringe
3. temperatureReflux the stirred mixture for 2.5 hours
4. temperaturecool
5. filtrationfilter
6. washwash the filter cake twice with acetone
7. concentrationconcentrate in vacuo
8. dissolutiondissolve the residue in ethyl acetate
9. washwash with NaHCO3 solution
10. extractionExtract the combined aqueous phases three times with ethyl acetate
11. washwash with saturated NaHCO3 and brine
12. dry with materialdry (MgSO4)
13. filtrationfilter
14. concentrationconcentrate in vacuo
15. customto afford an oil
16. customPurify the oil by flash chromatography (silica gel, 5.5×15.2 cm)
17. washeluting with ethyl acetate
18. washwith 5% methanol in dichloromethane after elution of the starting material
19. concentrationConcentrate the appropriate fractions