the mass is first thick and pasty; but soon becomes semi-fluid, and remains in this condition, gradually changing in colour from yellow to brown until towards the end of the operation, when it regains somewhat its original consistency. On cooling, the melt is dissolved in water, and the alkaline reddish-brown liquid (sodium phenate and excess of alkali) acidified with conc.

Fig. 15.

hydrochloric acid in the cold.

Phenol separate

out as a light yellow oil, which is extracted from the liquid with ether. The ethereal solution dehydrated over quicklime is distilled, first on the waterbath and then over the flame. The portion boiling at 175°-185° is nearly pure phenol. It distils as a colourless liquid, and solidifies at once on introducing a small crystal of the same substance.

Properties.-Colourless needles possessing a smell resembling camphor; m. p. 40°-41°; b. p. 182°; easily soluble in water, alcohol, and ether. It is coloured violet with ferric chloride, blue with bleaching powder solution; on the addition of bromine water a yellow flocculent precipitate of tribromophenol is formed. See also Liebermann's reaction (p. 36).

PREPARATION XIV.

ANISOL, C,H,O = CH.OCH.
(Methyl Phenate, Phenyl Methyl Ether.)

LITERATURE.-Cahours (1851), Ann. Ch. Pharm. 78,

Five grms. sodium cut into thin slices are dissolved in 100 c.c. pure methyl alcohol contained in a flask attached to a reflux condenser. To the solution, when cool, 20 grms. phenol are added and 40 grms. methyl iodide, and without removing the condenser

the whole heated on the water-bath for several hours until the solution has no longer an alkaline reaction. A portion of the methyl alcohol and methyl iodide are distilled off on the water-bath, and water added to the amber-coloured residue. After repeatedly washing with water to dissolve out the remainder of the methyl alcohol, a colourless oil separates out, which is extracted with ether, the ethereal solution dehydrated over fused calcium chloride, and distilled first on the water-bath until the ether has been driven off and then over the flame. Almost the whole of the residue distils at 150°-155°.

CH5OH + CH2ONa = CH2ONa + CH2OH

CHONa+ CHI

=

Sodium Phenate

C6H5OCH, + NaI
Phenyl Methyl Ether.

Properties.-Colourless liquid possessing an agree

able smell; b. p. 152°; sp. gr. '991 at 15o.

PREPARATION XV.

ORTHO- AND PARA-NITROPHENOL, CH¿NO

(1) NO, (1)

2

C6H4 (2) OH (4)

LITERATURE.-Hofmann (1857), Ann. Ch. Pharm. 103, 347; Fritsche (1859), Ann. Ch. Pharm. 110, 150; Kekulé, Lehrbuch d. org. chem. 3, 40.

To a mixture of 160 grms. nitric acid sp. gr. 1'34 and 320 grms. water, contained in a flask of about 1 litre capacity, 80 grms. melted phenol are gradually added in small quantities, and the contents of the flask well shaken. On the addition of the phenol, the liquid immediately changes to a deep brown or black colour, and a heavy dark brown oil separates out. When the whole of the phenol has been added, the mixture is allowed to stand for twelve hours. The oil has by that time collected at the bottom of the vessel, and may be freed from acid by repeatedly pouring in water, and carefully decanting. The contents of the flask consist of nearly equal quantities of para and ortho-nitrophenol, mixed with resinous products. In order to separate the two isomers the product is distilled in a current of steam (see Fig. 12) until the distillate is almost colourless. The ortho-compound distils into the receiver in the form of a yellow oil, which solidifies at the ordinary temperature to needle-shaped crystals. By recrystallisation from hot dilute alcohol it is obtained well crystallised and pure.

The solid residue contains the para-compound mixed with black resinous substances, from which it

is separated by repeatedly extracting with boiling water. The united portions of the aqueous extract are boiled with animal charcoal and filtered. The light brown filtrate is made slightly alkaline with caustic soda solution, concentrated to a small bulk and allowed to crystallise. The brownish crystals are separated from the mother-liquor by draining and pressing at the filter-pump. These may be purified by recrystallisation from water. To obtain the free para-compound the concentrated aqueous solution of the sodium salt is acidified with dilute hydrochloric acid, and the nitrophenol, which separates out as a crystalline precipitate, is filtered and recrystallised from hot dilute alcohol.

Properties. - Ortho- nitrophenol, sulphur-yellow needles, possessing a peculiar aromatic smell; m. p. 45°; b. p. 214°; distillable with steam; soluble in alcohol, ether, and hot water; less soluble in cold water.

Para-nitrophenol, colourless needles; m. p. 114°; easily soluble in alcohol and hot water; with difficulty soluble in cold water.