Abstract: Provided is a method for preparing fluralaner. The method includes: mixing 4-(5-(3,5-dichlorophenyl)-5-(trifluoromethyl)-4,5-dihydro-isoxazol-3-yl)-2-methyl-benzoic acid, a catalyst, an alcohol and an organic solvent to obtain a mixture, and subjecting the mixture to esterification to obtain an esterification solution containing 4-(5-(3,5-dichlorophenyl)-5-(trifluoromethyl)-4,5-dihydro-isoxazol-3-yl)-2-methyl-benzoate; and mixing the esterification solution with 2-amino-N-(2,2,2-trifluoroethyl)acetamide to obtain a mixed solution and subjecting the mixed solution to ester decomposition-amidation to obtain the fluralaner.

Abstract: The disclosure provides processes for preparing 5-fluoro-2-methyl-1-(4-methylthiobenzylidene)-3-indanacetonitrile and for preparing sulindac, relating to the field of medicine. The former comprises mixing 6-fluoro-2-methyl-1-indanone, cyanoacetic acid, a first organic solvent and an acetic acid-based catalyst to proceed with a first condensation reaction to give a first condensation reaction solution, which contains 5-fluoro-2-methyl-3-indanacetonitrile; and mixing the first condensation reaction solution, per se, with a base, a second organic solvent and 4-(methylthio)benzaldehyde to proceed with a second condensation reaction to give 5-fluoro-2-methyl-1-(4-methylthiobenzylidene)-3-indanacetonitrile. The process is a one-pot process without separation of 5-fluoro-2-methyl-3-indanacetonitrile from the solvent, shortening the synthetic route, simplifying the preparation process and improving the 5-fluoro-2-methyl-1-(4-methylthiobenzylidene)-3-indanacetonitrile yield.

Abstract: The disclosure provides processes for preparing 5-fluoro-2-methyl-1-(4-methylthiobenzylidene)-3-indanacetonitrile and for preparing sulindac, relating to the field of medicine. The former comprises mixing 6-fluoro-2-methyl-1-indanone, cyanoacetic acid, a first organic solvent and an acetic acid-based catalyst to proceed with a first condensation reaction to give a first condensation reaction solution, which contains 5-fluoro-2-methyl-3-indanacetonitrile; and mixing the first condensation reaction solution, per se, with a base, a second organic solvent and 4-(methylthio)benzaldehyde to proceed with a second condensation reaction to give 5-fluoro-2-methyl-1-(4-methylthiobenzylidene)-3-indanacetonitrile. The process is a one-pot process without separation of 5-fluoro-2-methyl-3-indanacetonitrile from the solvent, shortening the synthetic route, simplifying the preparation process and improving the 5-fluoro-2-methyl-1-(4-methylthiobenzylidene)-3-indanacetonitrile yield.

Abstract: The present invention provides a method for preparing levobunolol hydrochloride. In the present invention S-1-tert-butyl-epoxy methylamine is subjected to a substitution reaction with 5-hydroxy-1-tetralone, and acidified to obtain the target product levobunolol hydrochloride. The method provided by the present invention greatly improves the regioselectivity of the reaction, avoids the occurrence of side reactions, and effectively improves the yield and optical purity of levobunolol hydrochloride, with the yield being 87.3%, and the ee value being over 99%.

Abstract: The present invention provides a method for preparing levobunolol hydrochloride. In the present invention S-1-tert-butyl-epoxy methylamine is subjected to a substitution reaction with 5-hydroxy-1-tetralone, and acidified to obtain the target product levobunolol hydrochloride. The method provided by the present invention greatly improves the regioselectivity of the reaction, avoids the occurrence of side reactions, and effectively improves the yield and optical purity of levobunolol hydrochloride, with the yield being 87.3%, and the ee value being over 99%.