反应详情

2-bromo-7-nitro-5-trityl-pyrrolo[2,3-b]pyrazine (5 g, 10.30 mmol) dissolved in tetrahydrofuran (200.0 mL)/water (50.00 mL) and indium (11.83 g, 103.0 mmol) then HCl (20.60 mL of 6 M, 123.6 mmol) added. Indium dissolves then precipitates out over 5 minutes. Reaction mixture is filtered through celite, washing with EtOAc. Filtrate basified by careful addition of NaHCO3. Emulsion forms and mixture is filtered again before layers separated. Aqueous is extracted with EtOAc. Combined organics dried and concentrated in vacuo to a black foam. Residue is taken up in DCM and purified by chromatography eluting with 0-50% EtOAc—petroleum ether). Product obtained as a green/brown foam. Dried on high vacuum and taken directly on to acylation reaction. (3.43 g, 73%). 1H NMR (400.0 MHz, DMSO) δ 8.46 (s, 1H), 8.40 (s, 1H), 7.38-7.36 (m, H), 7.23-7.20 (m, 8H) and 3.32 (s, 7H) ppm; MS (ES+) 457.0

1. customthen precipitates out over 5 minutes
2. customReaction mixture
3. filtrationis filtered through celite
4. washwashing with EtOAc
5. additionFiltrate basified by careful addition of NaHCO3
6. filtrationEmulsion forms and mixture is filtered again before layers
7. customseparated
8. extractionAqueous is extracted with EtOAc
9. customCombined organics dried
10. concentrationconcentrated in vacuo to a black foam
11. custompurified by chromatography
12. washeluting with 0-50% EtOAc—petroleum ether)
13. customProduct obtained as a green/brown foam
14. customDried on high vacuum
15. customtaken directly on to acylation reaction