180914-87-8Relevant articles and documents
Method for preparing optically pure 5,7-difluoro-1,2,3,4-tetrahydronaphthalene-2-amine and salts thereof
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, (2021/10/27)
The invention discloses a method for preparing optically pure 5,7-difluoro-1,2,3,4-tetrahydronaphthalene-2-amine as shown in formulas a and b and salts thereof. The method comprises the following steps: (1) reacting 3,5-difluorophenylacetic acid with SOCl2 in the presence of a solvent to generate acyl chloride, and then carrying out Friedel-Crafts reaction on the acyl chloride and ethylene under the action of aluminum trichloride; (2) reacting 5,7-difluoro-3,4-dihydronaphthalene-2(1H)-ketone with amide in an organic solvent under an acid catalysis condition, and performing dehydrating to generate enamine; (3) performing catalytic hydrogenation on enamine in the presence of a chiral catalyst to prepare an optically pure intermediate amide; and (4) hydrolyzing the amide under an acidic or alkaline condition to obtain the optically pure 5,7-difluoro-1,2,3,4-tetrahydronaphthalene-2-amine (a or b) and the form of the salts thereof. The invention provides the method for preparing the optically pure 5,7-difluoro-1,2,3,4-tetrahydronaphthalene-2-amine and salts thereof, which is simple, convenient and easy to industrial production.
