参考路线：
To a solution of compound 36b (200 mg, 0.429 mmol) and K 2CO 3 (119 mg, 0.858 mmol) in DMSO (3 mL) was added (R) -N, N-dimethylpyrrolidin-3-amine (59 mg, 0.515 mmol) . The reaction mixture was stired at 22-30℃ for 4 h, then 50℃ for 1 h while color changed from brown to deep orange. The reaction mixture was added drop wise into H 2O (40 mL) under ice water bath. The precipitated solid was collected by filtration and washed with H 2O (15 mL × 3) , the filter cake was dissolved with CH 2Cl 2 (20 mL) , dried over Na 2SO 4 and concentrated in vacuum to give compound 52a (210 mg, 87.4%yield) as an orange solid.
