反应详情

To a stirring solution of #248 (600 mg, 2.61 mM) in 10 mL of dichloromethane, N,2-dimethylalanine (306 mg, 2.61 mM) was added followed by triethylamine (1.09 mL, 7.84 mM). The reaction was allowed to stir at room temperature for three hours. Dichloromethane was added to the reaction and the organic layer was washed three times with water and two times with brine. The organic layer was separated and then dried over sodium sulfate before being concentrated in vacuo. The crude residue was purified by silica chromatography (0-30% methanol in dichloromethane) on silica which had been previously neutralized with triethylamine yielding a white solid #249 (127 mg, 16%). LC-MS (Protocol Q): m/z 309.0 [M−H−], retention time=0.96 minutes.

1. washthe organic layer was washed three times with water and two times with brine
2. customThe organic layer was separated
3. dry with materialdried over sodium sulfate
4. concentrationbefore being concentrated in vacuo
5. customThe crude residue was purified by silica chromatography (0-30% methanol in dichloromethane) on silica which