Abstract: A method of preparing (S)-2-amino-5-methoxytetralin hydrochloride[(S)-2-amino-5-methoxyl-1,2,3,4-tetrahydronaphthalene hydrochloride], comprising the steps of: (1) producing a compound (I) by addition-elimination reaction of 5-methoxy-2-tetralone and R-(+)-a-phenylethylamine; (2) producing a compound (II) by reduction reaction of the compound (I) with a reducing agent; and (3) producing a compound (II) hydrochloride by reacting the compound (II) with a salt-forming agent, then carrying out reduction reaction with a palladium-carbon catalyst to produce (S)-2-amino-5-methoxytetralin hydrochloride. The method can significantly increase the yield of (S)-2-amino-5-methoxytetralin hydrochloride with short synthetic path, low preparation cost and less pollution, which is environmentally friendly and is suitable for medical industrialized production. The structural formulae of the compound (I) and the compound (II) are: respectively.

Abstract: A method of preparing (S)-2-amino-5-methoxytetralin hydrochloride[(S)-2-amino-5-methoxyl-1,2,3,4-tetrahydronaphthalene hydrochloride], comprising the steps of: (1) producing a compound (I) by addition-elimination reaction of 5-methoxy-2-tetralone and R-(+)-a-phenylethylamine; (2) producing a compound (II) by reduction reaction of the compound (I) with a reducing agent; and (3) producing a compound (II) hydrochloride by reacting the compound (II) with a salt-forming agent, then carrying out reduction reaction with a palladium-carbon catalyst to produce (S)-2-amino-5-methoxytetralin hydrochloride. The method can significantly increase the yield of (S)-2-amino-5-methoxytetralin hydrochloride with short synthetic path, low preparation cost and less pollution, which is environmentally friendly and is suitable for medical industrialized production. The structural formulae of the compound (I) and the compound (II) are: resepectively.