Condensation of 4-fluorophenylacetyl chloride (I) with ethylene in the presence of AlCl3 provided the beta-tetralone (II). After conversion of (III) into enamine (IV) upon reaction with pyrrolidine (III) in MeOH, alkylation with allyl bromide (V) afforded iminium salt (VI). Acid hydrolysis of (VI) generated the allyl tetralone (VII), which was subjected to reductive amination with ammonium acetate and sodium cyanoborohydride to produce the cis-1-allyl-2-aminotetralin (VIII) as the major isomer. Coupling of (VIII) with carboxylic acid (IX) using 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate (HBTU) gave amide (X), which was finally reduced to the target aminotetralin derivative with LiAlH4.

Condensation of 4-fluorophenylacetyl chloride (I) with ethylene in the presence of AlCl3 provided the beta-tetralone (II). After conversion of (III) into enamine (IV) upon reaction with pyrrolidine (III) in MeOH, alkylation with allyl bromide (V) afforded iminium salt (VI). Acid hydrolysis of (VI) generated the allyl tetralone (VII), which was subjected to reductive amination with ammonium acetate and sodium cyanoborohydride to produce the cis-1-allyl-2-aminotetralin (VIII) as the major isomer. Coupling of (VIII) with carboxylic acid (IX) using 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate (HBTU) gave amide (X), which was finally reduced to the target aminotetralin derivative with LiAlH4.