Pyrocatechol monomethyl ether

PYROCATECHOL MONOMETHYL ETHER (90-05-1) C7Hg02 Combustible solid (flash point 179°F/82°C). Reacts violently with strong oxidizers. Incompatible with sulfuric acid, nitric acid bases, caustics, amines, amides, inorganic hydroxides (form salts). On small fires, use dry chemical powder (such as Purple-K-Powder), Halon , or CO2 extinguishers. 

Guaiacol, CH30.C6H4.0H(1, 2), is so-called because it was first obtained from gum guaiacum. It is found among the products of the distillation of wood, and can be prepared from pyrocatechol, of which it is the monomethyl ether. It melts at 28.5° and boils at 205°. 

Protocatechuic acid is soluble in water, and melts at 199°. Ferric chloride colors its aqueous solution bluish-green, the color changing to blue and finally to red on the addition of alkalies. The acid reduces an ammoniacal solution of silver nitrate, but does not reduce Fehling s solution. It decomposes into pyrocatechol and carbon dioxide when distilled. Bromine in the cold forms bromoprotocatechuic acid at 100° the carboxyl group is eliminated and tetrabromopyrocatechol is formed. The monomethyl ether, C6H3(OH)(OCH3)COOH(4, 3, 1), is called vanillic acid, as it is formed by the oxidation of vanillin. The dimethyl ether, veratric acid, and the methylene ether, CH2 02 C6H3C00H, piperonylic add, are obtained from a number of substances which occur in nature. 

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