Acetic Anhydride → 2-(3-Chloro-4-acetamidophenyl)acetic acid

Participants

Reaction Steps

Acetic anhydride (152 mL, 1.6 moles) was added dropwise to a rapidly stirring mixture of 4-aminophenylacetic acid (195 grams, 1.3 moles) in acetic acid (600 mL) and water (250 mL) at room temperature. After a slight exotherm, the dark brown solution was stirred for one hour at room temperature. The solution was diluted with ethanol (500 mL) and water (250 mL), and a suspension of Calcium hypochlorite (340 grams, 2.3 moles) in water (1 L plus 500 mL rinse) was added portionwise. The temperature rose to 50° C. and the mixture was stirred for 16 hours at room temperature. The mixture was poured into ice-water (8 L) and extracted with ethyl acetate (3×2 L). The combined extracts were washed with saturated brine, dried over magnesium sulfate and concentrated in vacuo to a small volume. Hexane was added and the resulting precipitate filtered, washed with hexane and dried to give the title compound(180 grams) as a brown solid

Provenance & Evidence