Water → 5-(phenothiazin-3-ylideneamino)benzene-1,3-dicarboxylic Acid

Participants

Reaction Conditions

Reaction Steps

Phenothiazine (1.0 g, 5.0 mmol) and 5-aminoisophthalic acid (0.9 g, 5.0 mmol) were dissolved in MeOH (200 mL), cooled to 10° C. and treated with 1 M aqueous AgNO3 (30 mL, 30 mmol). After stirring at 10° C. for 30 minutes H2O (40 mL) was added and stirring continued for an additional 5 minutes. The solid product was then collected by filtration and washed with H2O (50 mL). The solid was dissolved in MeOH (500 mL) containing concentrated aqueous NH4OH (10 mL), stirred for 20 minutes then filtered to remove Ag. The filtrate was concentrated to ca. half its original volume under reduced pressure and refrigerated overnight at 5° C. The mixture was then filtered through Celite (Celite Corp.) and concentrated in vacuo until solid began to separate. The resulting solution (ca. 100 mL) was again filtered through Celite, diluted with ethyl acetate (900 mL) and allowed to stand for 15 minutes. The red solid that separated was collected by filtration, washed with ethyl acetate and dried to give 18(1.55 g, 82.5%).

Provenance & Evidence