85160-83-4

600-00-0

121-88-0

85160-83-4

1. 125 mM potassium carbonate was added to 100 mL of anhydrous N,N-dimethylformamide (DMF). 2. 50 mM 2-amino-5-nitrophenol was added to the above solution and stirred at room temperature for 1 hr until completely dissolved. 3. A DMF solution containing 50 mM ethyl 2-bromo-2-methylpropionate was added dropwise slowly in an ice bath. 4. After completion of the addition, the reaction mixture was kept in an ice bath with continued stirring for half an hour. 5. The reaction mixture was warmed slowly to room temperature and then heated to 90 °C for 12 hr. 6. After completion of the reaction, the reaction mixture was cooled and some solvent was removed by decompression distillation. 7. After the dropwise addition, the reaction mixture was kept in an ice bath with stirring for half an hour. 5. The reaction mixture was slowly warmed to room temperature and then heated to 90 °C for 12 hours. 6. After completion of the reaction, the reaction mixture was cooled and some of the solvent was removed by distillation under reduced pressure. 7. 300-500 mL of ice water was slowly added to the remaining solution with stirring to induce the precipitation of solids. 8. The mixture was kept in an ice bath with stirring for half an hour and then filtered to collect the solids. 9. The filter cake was vacuumed. 10. The solid was collected by filtration.9. The filter cake was dried under vacuum to give 8.32 g of the intermediate in brown powder form in 75.0% yield.10. The intermediate can be used directly in the subsequent reaction without further purification.