The invention relates to a method for simply and conveniently preparing high-purity lotinia, which comprises the following steps of: reacting 5-acetyl-3-methyl-2-thiophenecarboxylic acid with 2, 2, 2-trifluoro-1-trichlorophenyl ethyl-1-
ketone to obtain 3-methyl-5-(4, 4, 4-trifluoro-3-trichlorophenyl butyl-2-enoyl)
thiophene-2-
formic acid, and reacting the 3-methyl-5-(4, 4, 4-trifluoro-3-trichlorophenyl butyl-2-enoyl)
thiophene-2-
formic acid with 2, 2, 2-trifluoro-1-trichlorophenyl ethyl-1-
ketone to obtain 3-methyl-5-(4, 4, 4-trifluoro-3-trichlorophenyl butyl-2-enoyl)
thiophene-2-
carboxylic acid. Reacting the
isoxazole thiophene
formic acid compound with
hydroxylamine hydrochloride to obtain an
isoxazole thiophene formic acid compound; the preparation method comprises the following steps: reacting 5-[(5S)-5-trichlorophenyl-5-
trifluoromethyl-4, 5-dihydro-
isoxazole-3-yl]-3-methyl-thiophene-2-formic acid with (R)-1-(p-tolyl) ethyl-1-amine to obtain 5-[(5S)-5-trichlorophenyl-5-
trifluoromethyl-4, 5-dihydro-isoxazole-3-yl]-3-methyl-thiophene-2-formic acid; and finally, carrying out condensation on the product and 2-amino-N-trifluoroethyl
acetamide hydrochloride, so as to obtain the (5S)-configuration final product lotinib. The method has the advantages of short synthetic
route, simple process, mild reaction and high chiral purity and HPLC purity, and is especially suitable for large-scale production.