• Archives of Pharmacal Research
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• v.23 no.4
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• pp.329-331
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• 2000

4-(p-Chlorophenyl)tetralone (6) and 7-chloro-5-(p-chlorophenyl)tetralone (9) are key intermediates for the development of benzazepinone derivative haftens. These compounds could be synthesized from 4-phenyltetralone derivatives by triflic acid catalyzed Friedel-Crafts reaction. The reaction mechanism of Friedel-Crafts alkylation/acylation with lactones in triflic acid is presented. According to our tentative research, ring opening of protonated lactone (2) occurs in alkyl cleavage and the rate of the reaction is not dependent on concentration of triflic acid. So, alkylation of lactone in Friedel-Crafts reaction is presumed to be $A_{AL}$ 1. In second step, intramolecular acylation of the intermediates 4 to 6, 4 can be transformed to a triflic acid-carboxylic anhydride and then the cyclization is undergone after leaving of the triflate anion.

• YAKHAK HOEJI
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• v.36 no.4
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• pp.341-344
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• 1992

A facile method for tolmetin, which is a potent antiinflammatory agent, is described. Friedel-Crafts reaction of 1-methylpyrrole with ethyl ${\alpha}-chloro-{\alpha}-(methylthio)acetate$ (1) gave ethyl ${\alpha}-methylthio$-1-methyl-2-pyrroleacetate (4), which was readily converted into ethyl 1-methyl-2-pyrroleacetate (5) by reductive desulfurization with zinc dust in acetic acid. Tolmetin was synthesized by Friedel-Crafts acylation of (5) with p-toluoyl chloride, followed by hydrolysis of the resultant ethyl 5-(p-toluoyl)-1-methylpyrrole-2-acetate (6).

• Journal of the Korean Chemical Society
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• v.60 no.5
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• pp.374-377
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• 2016

• Bulletin of the Korean Chemical Society
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• v.22 no.10
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• pp.1063-1064
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• 2001

• Bulletin of the Korean Chemical Society
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• v.34 no.12
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• pp.3539-3540
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• 2013

• Bulletin of the Korean Chemical Society
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• v.32 no.12
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• pp.4163-4164
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• 2011

• Bulletin of the Korean Chemical Society
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• v.32 no.4
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• pp.1387-1390
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• 2011

• YAKHAK HOEJI
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• v.35 no.2
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• pp.119-122
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• 1991

A convenient method for the synthesis of ibuproxam, which is a non steroidal antiinflammatory agent, is reported. Friedel-Crafts reaction of isobutylbenzene with ethyl $\alpha$-chloro-$\alpha$-(methylthio)acetate (3) gives ethyl $\alpha$-methylthio-(p-isobutylpheny) acetate (4). Ethyl 2-methylthio-2-(4-isobutylphenyl) propionate (5) is obtained from methylation of the compound (4) with NaH and Mel. lbuproxam (7) is easily synthesized by reductive desulfurization of the compound (5) with zinc dust-acetic acid or Raney nickel, followed by treatment of the resultant ethyl 2-(4-isobutyl-pheny) propionate (6) with H$_{2}$NOH-HCI.

• YAKHAK HOEJI
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• v.35 no.2
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• pp.131-134
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• 1991

A new method for the synthesis of butibufen, which is a non steroidal anti-iriflammatory agent, is described. Friedel-Crafts reaction of isobutylbenzene with ethyl $\alpha$-chloro-.alpha.-(methylthio) acetate (1) gives ethyl $\alpha$-methylthio-(p-isobutylphenyl)acetate (2). Ethyl 2-methylthio-2-(4-isobutylphenyl)butyrate (3) is obtained from treatment of the compound (2) with NaH and Etl. Butibufen (5) is synthesized by reductive desulfurization of the compound (3) with zinc dust-acetic acid or Raney nickel, followed by hydrolysis of the resultant ethyl 2-(4-isobutylphenyl)butyrate (4).

• Archives of Pharmacal Research
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• v.27 no.12
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• pp.1189-1193
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• 2004

The total synthesis of norneolignans isolated from Krameria species, 2-aryl-5-(E)-propenylbenzofurans (5, 11), is described. The key step involves the one-pot reaction for 2-arylbenzofurans (2, 7) from 4-hydroxyphenylacetone with 4'-acetoxy-2-chloro-2-(methylthio)acetophenone (1) and 2-chloro-2-methylthio-(2',4',6'-trimethoxy)acetophenone (6) under Friedel-Crafts reactionconditions.