反应详情

To a stirred solution of 1-tert-butyl 3-methyl (3S)-piperazine-1,3-dicarboxylate (AA3) (1.0 eq.) and 6 N aq. HCl sol. (1.0 eq.) in 1,4-dioxane (1 M) was added a sol. of KOCN (2.0 eq.) in H2O (2 M). The reaction mixture was stirred at RT for 2 h, then the organic solvent was removed under reduced pressure. The desired product precipitated from H2O: it was filtered off, washed with cold water and dried at the high vacuum pump. Mother liquors were extracted with EtOAc, the organic phase was washed with brine, dried (Na2SO4), filtered and concentrated to dryness. The crude product was purified by flash chromatography on silica gel eluting with 10-100% EtOAc/petroleum ether to afford the desired product (H1) as a white powder which was combined with the previously isolated precipitate. 1H-NMR (300 MHz, DMSO-d6, 300K) δ 10.95 (1H, bs), 4.15-4.00 (2H, m), 3.97-3.75 (2H, m), 2.97-2.67 (3H, m), 1.42 (9H, s). MS (ES) C11H17N3O4 requires: 255, found: 256 (M+H)+.

1. customthe organic solvent was removed under reduced pressure
2. customThe desired product precipitated from H2O
3. filtrationit was filtered off
4. washwashed with cold water
5. customdried at the high vacuum pump
6. extractionMother liquors were extracted with EtOAc
7. washthe organic phase was washed with brine
8. dry with materialdried (Na2SO4)
9. filtrationfiltered
10. concentrationconcentrated to dryness
11. customThe crude product was purified by flash chromatography on silica gel eluting with 10-100% EtOAc/petroleum ether