Phenol → HCID 136117602, compound

Participants

Reaction Steps

20.7 g 2,4-dicyanoaniline were diazotised with 48 g nitrosylsulphuric acid at 0 to 5° C. in a solution comprising 200 ml glacial acetic acid, 40 ml of 85% phosphoric acid and 7.5 ml of concentrated aqueous sulphuric acid, and the batch was subsequently stirred for 1 hour. The reaction mixture was slowly added to a solution of 16 g phenol and 3 g urea in 120 ml water, the temperature being held at 10° C. and the pH being maintained at 6.3-6.5 with caustic soda solution. After stirring for a further 1 hour, the precipitate was filtered off under suction, washed with water, dried, and recrystallised from toluene. 30.3 g of orange-red 4-hydroxy-2′,4′-dicyano-azobenzene were obtained.

Provenance & Evidence