Citric Acid → HCID 86733942, compound

Participants

Reaction Steps

To 10-hydroxy-1'-methyl-9,10-dihydroanthracene-9-spiro-4'-piperidine (whose preparation is described in Example 2) (11.5 g.) in acetone (1250 ml.) is added, dropwise with stirring, a solution of oxidising agent (32 ml.), made from sodium dichromate dihydrate (10 g.), water (30 ml.) and concentrated sulphuric acid (7.4 ml.), made up to 50 ml. with water. After addition is complete, the reaction mixture is stirred for 1 hour and is then poured into water (3 l.) basified with 2N sodium hydroxide, and extracted three times with ether. The ether extracts are combined, washed with water and with brine and evaporated to give a brown oil which is dissolved in the minimum volume of chloroform and treated with an excess of saturated ethereal citric acid. The resulting precipitate is crystallised from methanol-ether to give 1'-methyl-10-oxo-9,10-dihydroanthracene-9-spiro-4'-piperidine citrate m.p. 172°-173°C.

Provenance & Evidence