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: 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.