Sodium Hydroxide → 9,9'-Spirobi[fluorene]-2,2'-dicarboxylic acid

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Reaction Steps

First 7.2 g of bromine and then a solution of 3.0 g of 2,2'-diacetyl-9,9'-spirobifluorene in a little dioxane are added dropwise at 0° C. while stirring to a solution of 6.0 g of sodium hydroxide in 30 ml of water. After stirring for a further hour at room temperature, the clear yellow solution is admixed with 1 g of sodium hydrogen sulfite dissolved in 20 ml of water. After acidification with concentrated hydrochloric acid, the precipitated colorless product is filtered off and washed with a little water. Recrystallization with ethanol gives 9,9'-spirobifluorene-2,2'-dicarboxylic acid as clear prisms (m.p. 352° C.).

Provenance & Evidence