Water → HCID 178421808, compound

Participants

Reaction Conditions

Reaction Steps

The pseudocumene layer from alkylation, containing 0.35-0.38 mole of 3-trifluoropropylamino-4-methylphenol was refluxed in a 1 L 3-necked flask fitted with thermometer, stirrer and Dean-Stark trap in order to remove water as the azeotrope. To the dry solution was added 30 g of phthalic anhydride. Condensation was effected by heating at reflux for 20 hours while removing water generated by reaction as the pseudocumene-water azeotrope. The solution turned red. When condensation was complete the solution was cooled to 100° C., 300 ml water and 25 g 50% sodium hydroxide added, and the pseudocumene removed by azeotropic distillation. The red dye which had crystallized out was separated by filtration and washed with 400 ml water (142 g wet paste). This filtercake was reslurried in 400 ml water and 10 g 50% sodium hydroxide, heated 30 minutes at 100° C., filtered again and washed with 400 ml water. Upon drying at 100° C., 40 g of dye zwitterion was obtained which melted at 258°-260° C.

Provenance & Evidence