4-Cyanophenol → HCID 54164796, compound

Participants

Reaction Steps

The sodium salt of p-hydroxybenzonitrile (1 ml) was heated with 2,4-dicyanonitrobenzene (1 mole) in dry dimethyl sulphoxide for 18 hours at 105° to form 4-(2,4-dicyanophenoxy) benzonitrile m.p. 222°-223°, which was recovered by dilution with water, and purified by crystallisation from acetic acid. This compound was hydrolysed with 60% w/w aqueous sulphuric acid (25 pts.) mixed with glacial acetic acid (10 parts), refluxing the mixture for 24 hours; on cooling, diphenyl ether 2,4,4'-tricarboxylic acid separated. The tricarboxylic acid was cyclized either (a) by heating to 300° for 5 minutes, or (b) dissolving in concentrated sulphuric acid, heating at 100° for 3 hours and subsequently diluting with water. The solid resulting from (a) or from (b) was recrystallised from dimethyl formamide to give xanthone-2,7-dicarboxylic acid identical with that prepared by Methods (i) and (ii).

Provenance & Evidence