Nitration of naphthalene to mononitronaphthalene

MANUFACTURE OF NITRO DERIVATIVES OF NAPHTHALENE NITRATION OF NAPHTHALENE TO MONONITRONAPHTHALENE 

Nitration grade naphthalene should be almost chemically pure, purified by sublimation or crystallization (pressed naphthalene). Sublimated naphthalene should not melt below 79.6°C, while the melting point of the pressed product (in lumps, 2-4 cm) should not be lower than 79.0°C. 

With concentrated sulphuric acid the naphthalene should not produce a darker shade than a pale reddish pink. 

This method has been applied at I. G. Leverkusen. It consists in charging naphthalene into a nitrator, containing a part of the spent acid and nitronaphthalene from the previous batch. To this the nitrating acid is added. 

The succession of operations is as follows. A cast iron nitrator of 7 m3 capacity 

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