Acidum Anisicum. Anisic Acid.
C8H8O3 = 152.064.
Anisic acid, C6H4(OCH3)COOH, may be prepared by the oxidation of anethol. It occurs in the form of colourless crystals, odourless when pure, but usually having a faint odour of anise. Melting-point, when pure, 184°; it should not melt under 180°. Boiling-point, 275° to 280°. It should not decolourise potassium permanganate, and should give no colour with ferric chloride. It may be titrated with alkali, using phenolphthalein as indicator.
Insoluble in water; soluble in alcohol (1 in 36), ether (1 in 50).
Action and Uses.—Anisic acid has the general properties of the benzene derivatives. It is used for the same purposes as acetylsalicylic and salicylic acids, which it closely resembles. It is administered usually as the sodium salt, which is prepared by neutralising the acid with sodium carbonate or bicarbonate.
Dose.—½ to 1 gramme (5 to 15 grains).