Guaiacol. Guaiacol. - (Syn., Guaiacolum, Ortho-di-oxybenzene-methyl-ester, Methyl-orthodioxybenzene, Methyl-pyrocatechin, Pyro-catechin (Catechol)-monomethylether; Fr. Gaiacol; Ger. Guajakol.)

II Aromatic Series 973

Manufacture: This monomethyl ether (ortho-dihydroxybenzene) is the chief constituent of creosote, and may be obtained (1) by distilling fractionally wood-tar creosote at 200-205° C. (392-401° F.), to get crude guaiacol, treating with ammonia to remove acid compounds, distilling, dissolving the lower boiling fraction in ether, treating with alcoholic solution of potassium hydroxide, to separate potassium guaiacol, C6H4KOCH3, which is insoluble in ether, washing well with ether, crystallizing from alcohol, decomposing with sulphuric acid, rectifying the liberated guaiacol; (2) synthetically, by heating at 170-180° C. (338-356° F.) equal molecules of pyrocatechin, potassium hydroxide, potassium methyl-sulphate - C6H4(OH)2 + KOH + KCH3SO4 = C6H4-OHOCH3 + K2SO4 + H2O, removing the resulting guaiacol by solution in alcohol or petroleum benzin, purifying by recrystallization; (3) by heating solution of metallic sodium, pyrocatechin, methyl iodide in methyl alcohol, freeing mixture from methyl alcohol, dissolving residue in sodium hydroxide solution, filtering, decomposing with hydrochloric acid; (4) by diazotizing and boiling ortho-anisidin with nitrous acid, decomposing the newly formed diazoanisol with sulphuric acid, distilling liberated guaiacol in a current of steam, redistilling, crystallizing. It is a colorless, yellowish, strongly refractive liquid or crystalline solid; odor agreeable, aromatic; darker on exposure to light and air; solid when liquefied, may remain so for some time, even at low temperature; melts at 28° C. (83° F.); dissolves in water (53), glycerin (.8), from which it separates on adding water; miscible with alcohol, chloroform, ether, acetic acid; sp. gr. 1.113; 85 p. c. distils at 200-210° C. (392-410° F.); incinerate 1 Gm. - ash .1 p. c. Tests: 1. Add to alcoholic solution 10 Ml. (Cc.) a drop of ferric chloride T. S. - an immediate blue color, changing to emerald-green, yellowish. 2. Shake 2 Ml. (Cc.) with purified petroleum benzin 4 Ml. (Cc.) - separates on standing into 2 distinct, clear layers; failure to separate or permanent turbidity indicates impurities (oily hydrocarbons, etc.). Should be kept dark, in well-closed containers. Dose, eij - 10 (.13-.6 Ml. (Cc.)).

Preparations. - 1. Guaiacolis Carbonas. Guaiacol Carbonate. (Syn., Guaiacol. Carb., Duotal; Fr. Carbonate de Gaiacol; Ger. Guajacolcarbonat, Kohlensaure-Guajacylather.)

II Aromatic Series 974

Manufacture: Pass slowly carbonyl chloride, COCl2 (phosgene gas), into guaiacol previously dissolved in sodium hydroxide solution, forming sodium chloride and guaiacol carbonate, the latter being insoluble separates, which is washed with solution sodium hydroxide, and crystallized from alcohol. It is a crystalline powder, odorless, tasteless, slight aromatic odor and taste; soluble in alcohol (60), chloroform (1), ether (18), benzene, slightly in glycerin, fixed oils; insoluble in water, melts at 85° C. (185° F.). Tests: 1. Saturated alcoholic solution + ferric chloride T. S. - no bluish-green color (abs. of free guaiacol); not acid; incinerate 1 Gm. - ash .1 p. c. Impurities: Free guaiacol, readily carbonizable substances, etc. Dose, gr. 5-30 (.3-2 Gm.).

Unoff. Prep.: Petroxolinum Guaiacolis, 20 Gm., oleic acid 5, liquid petroxolin 75.

Properties and Uses. - For the same purposes as creosote, but is less valuable and irritating to the intestinal canal and kidneys; phthisis, external tubercle, lupus, cough, expectoration, typhoid and other fevers, local anaesthesia, neuralgia, antiseptic.

Thymolis Iodidum. Thymol Iodide. - (Syn., Thymol. Iod., Aris-tolum, Aristol. Dithymoldiiodide; Fr. Diiododithymol, Dithymol biiode; Ger. Dithymoldijodid, Annidalin, Thymotol.)

II Aromatic Series 975

Manufacture: This is obtained by the condensation of 2 molecules of thymol, and the introduction of 2 atoms of iodine into the phenolic-groups of the thymol; potassium iodide being dissolved in a solution of iodine, and the thymol in a 12 p. c. solution of sodium hydroxide, the two solutions mixed, precipitate washed and dried; it is chiefly dithymol-diiodide, and contains, when dried to constant weight, 43 p. c. of iodine. It is a reddish-yellow, bulky powder, slight, aromatic odor; insoluble in water, glycerin, slightly soluble in alcohol, readily so in chloroform, ether, collodion, fixed or volatile oils (leaving slight residue). Tests: 1. Heat with sulphuric acid - decomposed with separation of iodine. 2. Dried to constant weight - loses 5 p. c; incinerate .5 Gm. at low red heat - ash 1.5 p. c. Impurities: Alkalies, free iodine, halogen salts. Should be kept dark, in well-closed containers.

Properties and Uses. - Antiseptic. Similar to and a substitute for iodoform in skin diseases (lupus, psoriasis, etc.), tertiary syphilis. Apply in powder or ointment, with wool fat, flexible collodion, etc.

Resorcinol. Resorcinol, C6H4(OH)2. - Fr. res (in) + orc(hella) + in + (phen)ol - i. e., resinous and peculiarly colored phenol substance). (Syn., Resorcin., Resorcinum, Metadihydroxybenzene; Fr. Resorcine; Ger. Resorcin.)

II Aromatic Series 976

Manufacture: While this diatomic phenol may be made by fusing different resins, as galbanum, guaiac(um), ammoniacum, asafetida, etc., with caustic alkalies, or by the reaction of fused sodium hydroxide upon sodium metabenzene disulphonate, it is obtained mostly by heating benzene with fuming sulphuric acid (4) at 257° C. (494° F.), forming benzene metadisulphonic acid, C6H(HSO3)2, which is dissolved in water, neutralized with milk of lime, decomposed with sodium carbonate, the solution of sodium benzene-metadisulphonate evaporated to dryness, residue fused 8-9 hours with sodium hydroxide (2.5), yielding sodium resorcin(ol), C6H4(ONa)2, and sodium sulphite; boil aqueous solution of saline mass to expell SO2, extract tar-like residue with ether, distil, leaving impure resorcinol, which is purified by sublimation and recrystallization from water. It is in colorless, nearly colorless, needle-shaped crystals, or powder, faint, peculiar odor, sweetish, bitter taste, pinkish on exposure, soluble in glycerin, ether, water (.9), hot water (.2), alcohol (.9), slightly in chloroform, melts at 110° C. (230° F.); aqueous solution (1 in 20) neutral, faintly acid; contains 99.5 p. c. of resorcinol. Tests: 1. Dissolve .1 Gm. in 1 Ml. (Cc.) of potassium hydroxide T. S., add 1 drop of chloroform, heat - intense crimson color, changing to a pale straw-yellow on adding slight excess of hydrochloric acid. 2. Aqueous solution (1 in 20) gently warmed - no odor of phenol; incinerate 2 Gm. - ash .05 p. c. Impurities: Catechol, quinol, etc. Should be kept dark, in well-closed containers. Dose, gr. 2-5 (.13-.3 Gm.).