Abstract: The present invention discloses the preparation method of cis-p-menthane-1,8-di-secondary amine compounds and their application in weed control. The preparation method is as follows: cis-p-menthane-1,8-di-Schiff base compounds are used as the raw material, and the reducing agent is added in batches into the raw material in a polar organic solvent at ?10˜50° C. to react for 1˜24 h; after the reaction is complete, the reaction solution is quenched with distilled water and extracted with dichloromethane, and the extract phase is dried with anhydrous sodium sulfate, filtered with a filter and then distilled under reduced pressure to obtain crude cis-p-menthane-1,8-di-secondary amine compounds, which are purified into the pure product through recrystallization or silica gel column chromatography.

Abstract: This invention discloses a type of 1,8-bis(Schiff base)-p-menthane derivatives as well as their preparation method and applications. The reaction of 1,8-diamino-p-menthane with a substituted benzaldehyde was carried out in a polar organic solvent at 0° C.-75° C. for 1-48 h. After the completion of the reaction, part of the solvent was distilled off to perform recrystallization to get a 1,8-bis(Schiff base)-p-menthane derivative, whose pre-emergence herbicidal activity against ryegrass was determined by using the Petri dish seed germination method. The 1,8-bis(Schiff base)-p-menthane derivatives, obtained with this method in high yield and mild reaction conditions, have a good inhibitory effect on the growth of annual ryegrass, and low toxicity.

Abstract: This invention discloses a type of 1,8-bis(Schiffbase)-p-menthane derivatives as well as their preparation method and applications. The reaction of 1,8-diamino-p-menthane with a substituted benzaldehyde was carried out in a polar organic solvent at 0° C.-75° C. for 1-48 h. After the completion of the reaction, part of the solvent was distilled off to perform recrystallization to get a 1,8-bis(Schiff base)-p-menthane derivative, whose pre-emergence herbicidal activity against ryegrass was determined by using the Petri dish seed germination method. The 1,8-bis(Schiff base)-p-menthane derivatives, obtained with this method in high yield and mild reaction conditions, have a good inhibitory effect on the growth of annual ryegrass, and low toxicity.

Abstract: Disclosed is a process for preparing isopimaric acid, comprising the following steps: First step: dissolving thermally isomerized rosin in acetone, adding in drops a solution of isobutanolamine in acetone to form a precipitate, standing, filtering, washing with ethanol, and drying to obtain crude ammonium salt of isopimaric acid; recrystallizing the crude ammonium salt of isopimaric acid according to multi-recrystallization, and drying to obtain purified crystal of ammonium salt of isopimaric acid; Second step: dissolving the purified crystal of ammonium salt of isopimaric acid obtained in the first step in ether, adding hydrochloric acid in portions until the crystal of ammonium salt of isopimaric acid disappears, removing a water layer and washing the ether layer with water to neutral, evaporating the ether, dissolving the residue in acetone, adding water slowly into the solution dropwise until crystals cease to grow, then filtering and drying to obtain purified isopimaric acid.

Abstract: A method for preparing pimaric acid type resin acids includes: step (1) adding refined resin acid, turpentine, or rosin along with maleic anhydride at a mass ratio of 1:0.3-1.5 into a reaction bottle, dissolving the ingredients into a C1-C10 lower fatty acid solvent, the mass ratio of the C1-C10 low fatty acid to refined resin acid is 0.05-30:1, then carrying out additional reaction by heating directly or with assistance of a microwave, subsequently cooling, crystallizing, filtering, and washing; and step (2) combining the filtrates collected in step (1), stripping the solvent by vacuum distillation to obtain pimaric acid type resin acid coarse product, dissolving the resulting coarse product in NaOH aqueous solution to prepare aqueous solution of pimaric acid type resin acid salt, adjusting the pH to 6-14 with a mineral acid or an organic acid, and either directly purifying or acidifying followed by purifying to obtain the final product.

Abstract: A method for preparing pimaric acid type resin acids includes the following steps: step (1) adding refined resin acid, turpentine, or rosin along with maleic anhydride at a mass ratio of 1:0.3-1.5 into a reaction bottle, dissolving the ingredients into a C1-C10 lower fatty acid solvent, the mass ratio of the C1-C10 low fatty acid to refined resin acid is 0.05-30:1, then carrying out additional reaction by heating directly or with assistance of a microwave, subsequently cooling, crystallizing, filtering, and washing; and step (2) combining the filtrates collected in step (1), stripping the solvent by vacuum distillation to obtain pimaric acid type resin acid coarse product, dissolving the resulting coarse product in NaOH aqueous solution to prepare aqueous solution of pimaric acid type resin acid salt, adjusting the pH level to 6-14 with a mineral acid or an organic acid while stirring, and either directly purifying or acidifying followed by purifying, the resulting precipitation to obtain the final product.

Abstract: A method for preparing pimaric acid type resin acids includes the following steps: step (1) adding refined resin acid, turpentine, or rosin along with maleic anhydride at a mass ratio of 1:0.3-1.5 into a reaction bottle, dissolving the ingredients into a C1-C10 lower fatty acid solvent, the mass ratio of the C1-C10 low fatty acid to refined resin acid is 0.05-30:1, then carrying out additional reaction by heating directly or with assistance of a microwave, subsequently cooling, crystallizing, filtering, and washing; and step (2) combining the filtrates collected in step (1), stripping the solvent by vacuum distillation to obtain pimaric acid type resin acid coarse product, dissolving the resulting coarse product in NaOH aqueous solution to prepare aqueous solution of pimaric acid type resin acid salt, adjusting the pH level to 6-14 with a mineral acid or an organic acid while stirring, and either directly purifying or acidifying followed by purifying, the resulting precipitation to obtain the final product.

Abstract: Disclosed is a process for preparing isopimaric acid, comprising the following steps: First step: dissolving thermally isomerized rosin in acetone, adding in drops a solution of isobutanolamine in acetone to form a precipitate, standing, filtering, washing with ethanol, and drying to obtain crude ammonium salt of isopimaric acid; recrystallizing the crude ammonium salt of isopimaric acid according to multi-recrystallization, and drying to obtain purified crystal of ammonium salt of isopimaric acid; Second step: dissolving the purified crystal of ammonium salt of isopimaric acid obtained in the first step in ether, adding hydrochloric acid in portions until the crystal of ammonium salt of isopimaric acid disappears, removing a water layer and washing the ether layer with water to neutral, evaporating the ether, dissolving the residue in acetone, adding water slowly into the solution dropwise until crystals cease to grow, then filtering and drying to obtain purified isopimaric acid.