反应详情

A solution of 5-bromo-3-((trimethylsilyl)ethynyl)pyrazin-2-amine (Compound C-2) PTSA salt 3 (2350 g, 5.31 mol) in EtOAc (11.5 L) is stirred with a 20% w/w aq. solution of KHCO3 (4.5 kg, 1.5 eq.) for at least 30 min. The layers are separated and the organic layer is concentrated then dissolved in EtOAc (7 L) and added to a reactor. DMAP (19.5 g, 0.16 mol) is added followed a solution of Boc2O (2436 g, 11.16 mol) in EtOAc (3 L) is added lowly. The reaction is stirred for at least 30 min to ensure complete reaction then activated charcoal (Darco G-60, 720 g) and Celite (720 g) are added and stirred for at least 2 h. The mixture is filtered washing the solid pad with EtOAc (2×1.8 L). The filtrate is concentrated to afford tert-butyl N-tert-butoxycarbonyl-N-[5-bromo-3-((trimethylsilyl)ethynyl)pyrazin-2-yl]carbamate (Compound C-3) that is used directly in the next step.

1. customThe layers are separated
2. concentrationthe organic layer is concentrated
3. dissolutionthen dissolved in EtOAc (7 L)
4. additionadded to a reactor
5. additionis added lowly
6. customreaction
7. stirringstirred for at least 2 h
8. filtrationThe mixture is filtered
9. washwashing the solid pad with EtOAc (2×1.8 L)
10. concentrationThe filtrate is concentrated