Benzoic acid, 4-(acetyloxy)- → p-Acetoxybenzoyl chloride

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Reaction Steps

A solution (20 ml.) of thionyl chloride containing 3.0 g of 4-acetoxybenzoic acid (Preparation 5) is refluxed for 3 hours. After evaporation of excess thionyl chloride, 4-acetoxybenzoyl chloride is obtained and dissolved in 15 ml. THF and 15 ml. acetone at 5°. This solution is added over 30 minutes to 2 g. of sodium azide in 10 ml. of water. The mixture is extracted with 2×75 ml. of toluene and the toluene solution washed several times with water. After drying the toluene solution containing the 4 acetoxybenzoyl azide with anhydrous magnesium sulfate, the mixture is filtered and the filtrate refluxed for one hour. The resulting 4-acetoxyphenyl isocyanate, in toluene, is cooled to 5° and reacted with 2.2 g. of 2-(endobicyclo[3.1.0]hex-6-yl)ethylamine. The product is a mixture of 4-acetoxy-[2-(endobicyclo[3.1.0]hex-6-yl)-ethyl]phenylurea and 4-hydroxy-[2-(endobicyclo[3.1.0]hex-6-yl)phenylurea in a ratio of 1:1. This mixture, in a solution of 50 ml. of methanol, is reacted with 10 ml. of a solution of 10% aqueous sodium hydroxide at 60° for 15 minutes. The resulting solution is then acidified with 6N hydrochloric acid. This mixture is extracted into 150 ml. of methylene chloride (CH2Cl2) and this extract washed with water, dried over magnesium sulfate and filtered. After chromatographing over silica gel, 1.7 g. of 4-hydroxy[2-(endobicyclo[3.1.0]hex-6-yl)ethyl]phenylurea are isolated.

Provenance & Evidence