4-Hydroxybenzaldehyde → 1-(p-Carboxyphenyl)-3-methyl-4-(p-hydroxybenzylidene)-2-pyrazolin-5-one

Participants

Reaction Steps

218 g (1 mole) of 1-p-carboxyphenyl-3-methyl-2-pyrazolin-5-one were suspended in 600 ml of dimethylformamide. The mixture obtained was heated with stirring to 100° C., whereupon a solution of 122 g (1mole) of p-hydroxybenzaldehyde in 400 ml of methanol was added. The dissolution of both compounds was complete. The dye started crystallizing after some 30 min. The heating was stopped after 2 h and the reaction mixture was allowed to cool down to room temperature. The dye was filtered with suction and rinsed with methanol.

Provenance & Evidence