2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → HCID 57592527, Verbindung

To a cooled (−78° C.) solution of 2,5-dibromofurane (3.06 g, 8.88 mmol) in anhydrous diethyl ether (50 ml) was added n-Butyllithium (3.9 ml of 2.5M solution in Hexanes, 9.77 mmol). The mixture was stirred at this temperature for 90 minutes before the addition of 2-chloropyrimidine. The mixture was stirred for a further 30 minutes before being warmed to room temperature and stirred for further 2 hours. DDQ (2 g, 8.88 mmol) was them added to the solution which was stirred for 30 minutes before being concentrated in vacuo to give a thick brown syrup. The syrup was dissolved in EtOAc and washed with saturated sodium carbonated solution. The organic extract was removed, dried (MgSO4), filtered and concentrated in vacuo to give a crude residue which was purified by flash chromatography (SiO2) (100% hexane going to 7:2—hexane:EtOAc) to give the title compound (3.06 g, 40.20%) in pure form. m/z (LC-MSW, ESP):346 [M+H]+, R/T=4.41 mins

1. stirringstirred for further 2 hours
2. additionadded to the solution which
3. stirringwas stirred for 30 minutes
4. concentrationbefore being concentrated in vacuo
5. customto give a thick brown syrup
6. washwashed with saturated sodium carbonated solution
7. extractionThe organic extract
8. customwas removed
9. dry with materialdried (MgSO4)
10. filtrationfiltered
11. concentrationconcentrated in vacuo
12. customto give a crude residue which
13. customwas purified by flash chromatography (SiO2) (100% hexane going to 7:2—hexane:EtOAc)

ORD-Eintrag

ord-e63c85de40f042aaa9cf7b7f8d4fbffa

Quelldatensatz

uspto-grants-2009_03

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07504397B2