O-Phthalyl chloride, symmetrical

Pure symmetrical o-phthalyl chloride cannot be obtained, even by recrystallization from carbon tetrachloride. A product melting at 16° may be obtained by distilling the unsymmetrical phthalyl chloride at atmospheric pressure. [Pg.90]

Symmetrical o-phthalyl chloride has been prepared by heating phthalic anhydride and phosphorus pentachloride in sealed tubes.1 This method is not convenient for the preparation of large quantities. [Pg.90]

Attempts have been made to prepare pure symmetrical o-phthalyl chloride by repeatedly heating the crude chloride,... [Pg.90]

A. Symmetrical o-Phthalyl Chloride A mixture of 148 g. (i mole) of phthalic anhydride (Note i) and 220 g. (r.o6 moles) of phosphorus pentachloride (Note 2) is placed in a 500-cc. Claisen flask. The flask is equipped with a reflux condenser, the upper end of which is provided with a calcium chloride tube, and the side-arm of the flask is closed with a cork. The flask is inclined slightly so that any phosphorus oxychloride which collects in the stoppered side-arm will run back into the flask. After heating in an oil bath at 150° for twelve hours, the air condenser and the stopper in the end of the side-arm are removed, and the flask is connected to a water-cooled condenser. I hc temperature is then raised gradually to 250 , during which... [Pg.45]

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