2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → [5-Bromo-4-(4-chlorobenzyl)-7-fluoro-1-oxo-1,2,3,4-tetrahydrocyclopenta[b]indol-3-yl]acetic acid methyl ester

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Reaction Steps

The methyl ester of the compound of Example 1 step 5 (1.00 g, prepared by treating the corresponding acid with excess diazomethane) in 10 mL of a 9:1 THF/H2O solution was treated with 2.52 g of DDQ. The reaction mixture was allowed to stir at room temperature overnight. The reaction mixture at this time was poured into a separatory funnel containing EtOAc and brine. The combined organic layers were washed with water, brine, dried over anhydrous MgSO4 and concentrated. The resulting material was further purified by flash chromatography eluting with 30% EtOAc/hexane. The chromatography procedure was repeated an additional two times. 350 mg of the above ketone was obtained as a grey solid.

Provenance & Evidence