From 1858 to 1861 methylated spirit was duty-free when it was required for manufacturing processes, and the methylation or "denaturizing" was carried out in accordance with a prescribed process.
It is apparently a tropidine monocarboxylic acid, for on exhaustive methylation it yields cycloheptatriene-I.
The potassium salt of the iso-diazo hydroxide yields on methylation a nitrogen ether, R N(CH 3) NO, whilst the silver salt yields an oxygen ether, R N: N OCH 3.
They behave, however, as tautomeric substances, since their alkali salts on methylation give nitrogen ethers, whilst their silver salts yield oxygen ethers: potassium salt - R N(CH 3).NO 2 nitramine.
Guaiacol may be obtained directly from beechwood tar, from pyrocatechin by methylation with potash and potassium methyl sulphate at 180°, or from anisol by nitration, reduction of the ortho-nitroanisol to amino-anisol, which is then diazotized and boiled with water.