Sulfuric Acid → 2,3-Dichloro-1,4-benzoquinone

1,4-Benzoquinone (2.01 g, 18.59 mmol) was dissolved in dry ether (50 mL) and dry chloroform (20 mL). The flask was placed under a constant flow of nitrogen and sulfuryl dichloride (5.02 g, 37.2 mmol) added dropwise over 15 minutes at 0° C. After 30 minutes the mixture was warmed to room temperature, stirred for another 30 minutes, returned to the ice-bath and treated with Et2O (25 mL) and conc. H2SO4 (30 mL). After 45 minutes the mixture was poured onto ice-water and extracted with further Et2O (3×75 mL). The combined organics were dried (MgSO4), filtered and concentrated to ca. 125 mL volume, whereupon silver oxide (9.96 g, 43 mmol) was added and the mixture stirred in the abscence of light for 1 hour. The mixture was filtered through celite, washing with ether and chloroform. Evaporation of the filtrate afforded an orange/yellow solid. The mixture was purified by flash chromatography, loading onto silica, eluting with a gradient of 0 to 20% EtOAc/Iso-Hexanes, holding at 9%, then re-purified by flash chromatography, loading onto silica, eluting with a gradient of 5 to 60% EtOAc/Iso-Hexanes, holding at 35%. This afforded compound x (1.15 g, 34.9%) as a bright yellow powder.

1. additionadded dropwise over 15 minutes at 0° C
2. additionAfter 45 minutes the mixture was poured onto ice-water
3. extractionextracted with further Et2O (3×75 mL)
4. dry with materialThe combined organics were dried (MgSO4)
5. filtrationfiltered
6. additionwas added
7. stirringthe mixture stirred in the abscence of light for 1 hour
8. filtrationThe mixture was filtered through celite
9. washwashing with ether and chloroform
10. customEvaporation of the filtrate
11. customafforded an orange/yellow solid
12. customThe mixture was purified by flash chromatography
13. washeluting with a gradient of 0 to 20% EtOAc/Iso-Hexanes
14. customre-purified by flash chromatography
15. washeluting with a gradient of 5 to 60% EtOAc/Iso-Hexanes

ORD record

ord-e9e6d03e5fc448f29431035eecf7b2bf

Source dataset

uspto-grants-2013_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08614237B2