反应详情

A product of Step C (0.22 g; 0.904 mmol), HCl×NH2OH (0.16 g; 2.3 mmol) and DIPEA (0.48 ml; 5 mmol) in anhydrous EtOH (3.5 ml) was refluxed for 2 h under N2. The solvents were removed under reduced pressure and the residue was diluted to 30 ml with EtOAc, washed with H2O (2×5 ml), brine, dried over anhydrous MgSO4, filtered and the filtrate evaporated to dryness to give the title compound (0.25 g; 100%) as colourless foam, which was used in next step without further purification.

1. customThe solvents were removed under reduced pressure
2. additionthe residue was diluted to 30 ml with EtOAc
3. washwashed with H2O (2×5 ml), brine
4. dry with materialdried over anhydrous MgSO4
5. filtrationfiltered
6. customthe filtrate evaporated to dryness