| 摘要 |
Tetrahydroabietic acid is produced by hydrogenating melted or dissolved colophony in the presence of catalysts.ALSO:Resin acids are converted into their anhydrides, e.g. by boiling the acids with acetic anhydride, and the products, which may be purified, e.g. by recrystallization, are treated with compounds which are known to form derivatives by reaction with acid anhydrides, e.g. the products are treated with alcohols, phenols, amides, amines, hydroxyamines, or esters from acids which form distillable anhydrides, or mixtures thereof. Among the resin acids which may be used are abietic acid, pyroabietic acid, tetrahydroabietic acid, tetrahydroxyabietic acid or halogenized abietic acids. The process may be carried out at ordinary or increased pressure, and diluents such as anhydrous ether, anhydrous alcohol, benzene, and mixtures of ether and benzene may be employed. In the examples, (1) abietic acid anhydride is prepared from colophony and acetic anhydride, and may be purified by recrystallization. The crude or purified anhydride is dissolved in excess of ethyl alcohol and refluxed at 80-150 DEG C. for a few hours, less time being required when excess pressure is used. The abietic acid produced may be removed by treatment with dilute alkalis, and the ethyl ester is purified by distillation at 10 mm. pressure. (2) The various butyl alcohols are substituted for the ethyl alcohol of the previous example. (3) The phenol ester of abietic acid is produced by heating the anhydride with phenol at 120-150 DEG C. for 1 to 2 hours. Excess phenol may be distilled off or washed out together with the abietic acid formed by means of alkalis. The ester is purified by distillation as before. (4) A solution of abietic anhydride is stirred while ammonia is passed in. The solvent is then distilled off, and the ammonium salt formed is removed from the abietic amide by direct washing or after decomposition with acids. The amide is purified by distillation. (5) A process analogous to (3) is used for the preparation of abietic acid anilide, and excess aniline is removed by distillation or by washing with acid before the removal of abietic acid by washing with alkali. (6) Diethyl phthalate is heated with abietic acid anhydride in an atmosphere of carbon dioxide with or without increased pressure for some hours. The product is distilled in vacuo, and simultaneously separated into phthalic anhydride and abietic acid ethyl ester. (7) Pyroabietic acid and (8) tetrahydroxyabietic acid are converted to their anhydrides and used in place of the abietic anhydride of Examples 1-6. Pyroabietic acid is produced by prolonged heating of colophony, tetrahydroxyabietic acid by oxidation of colophony with potassium permanganate, tetrahydroabietic acid by hydrogenating colophony in the presence of catalysts, and halogenized abietic acids by passing chlorine or other halogen through molten or dissolved colophony. |
