Example 50
Synthesis of AM393-A.
To a cooled (0° C.) solution of NaH (190 mg, 50% in mineral oil, 4.0 mmol) in DMF (5 mL) was added AM351-A (400 mg, 1.6 mmol) and the mixture was stirred at room temperature for 20 min. The reaction mixture was cooled to 0° C. and methyl iodide was added. The reaction mixture was stirred with slow warming to room temperature for 1 h. The reaction mixture was quenched with ice-cold water (10 mL) and the product was extracted with DCM (20 mL×3). The combined organic layer was washed with brine (20 mL) and dried over anhydrous Na2SO4. The solvent was removed in vacuo and the residue was purified by column chromatography on silica gel (PE:EtOAc=90:10˜85:15) to give AM393-A (360 mg, 85%) as a yellowish gum.
Compound AM393 (120 mg, 99%, a grey solid) was synthesized in a similar procedure used for AM351 from AM351-I)
