反应详情

1-tert-Butoxycarbonyl-3-oxopiperazine (see Tetrahedron Lett. (1980), 21(32), 3019-20 for outline of synthesis, 5 g) was dissolved in dry DMF (75 ml) and potassium tert-butoxide (3.08 g) was added. The mixture was stirred at ambient temperature for 1 hour, then iodomethane (3.9 g) was added, and stirring continued at the same temperature for 2.5 hours. Solvent was evaporated, and the residue chromatographed on silica, using as eluant a gradient increasing in polarity from 0 to 100% ethyl acetate in iso-hexane. Relevant fractions were combined and evaporated to give 1-tert-butoxycarbonyl-4-methyl-3-oxopiperazine (3.92 g).

1. stirringstirring
2. waitcontinued at the same temperature for 2.5 hours
3. customSolvent was evaporated
4. customthe residue chromatographed on silica
5. temperaturea gradient increasing in polarity from 0 to 100% ethyl acetate in iso-hexane
6. customevaporated