urbaf2

OTHER NITRO DERIVATIVES OF PHENOLS 535

manufacture). After the temperature in the nitrator has attained 45°C (which requires

about 45 mm), the flow of sulphocresol is stopped.

The temperature rises spontaneously to 85°C and sulphocreso1 is then run in

again at such a rate as to introduce the whole lot in no more than 2 hr. Towards

the end of the process the temperature attains 100-103°C. The reaction mixture

is allowed to remain at rest for half an hour, then compressed air is gently blown

through for about 20 min, thus causing the temperature to fall to 90°C. A further

temperature fall to 70°C is achieved by blowing air strongly for about one hour.

At this stage of the process the granulation of the Cresilite begins, depending on

the cooling rate and on the intensity of the air blowing.

After granulation has been completed, the nitrator contents are allowed to remain

at rest for 12-15 hr, then without any dilution the spent acid are drawn off by means

of an aluminium siphon. The spent acid is passed through an asbestos filter to retain

any Cresilite granules carried away.

The product obtained is in the form of yellowish-brown granules, with a melting

point of 101-103°C.

NITRO DERIVATIVES OF ARYLPHENOLS

NITRO DERIVATIVES OF 3-HYDROXYDIPHENYL

Colbert, Fox and Matuszak [26] nitrated 3-hydroxydiphenyl and obtained

a number of its nitro derivatives:

NITRO DERIVATIVES OF POLYHYDRIC PHENOLS

Among polyhydric phenols, only the nitro derivatives of resorcinol have gained
considerable practical importance. The nitro derivatives of phloroglucinol may

also be of some value. Both phenols have hydroxyl groups in the meta position

to each other, thus enabling the introduction of three nitro groups. Among dinitro

derivatives, those of pyrocatechol have found some uses.