Boron Trichloride → 2'-Amino-3'-methyl-4'-methoxyacetophenone

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Reaction Steps

Optionally substituted 2-(thiazol-2-yl)-4-chloro-7-alkoxy-8-alkyl-quinoline 2-phenyl-4-chloro-7-alkoxy-quinolines, such as 2-(4-isopropylthiazol-2-yl)-4-chloro-7-methoxy-8-methyl-quinoline, can be synthesized as shown in Scheme XIII. 3-Alkoxy-2-alkyl-anilines, such as 3-methoxy-2-methyl-aniline, can react with acetonitrile (CH3CN) in the presence of Lewis acids, for example boron trichloride and aluminum trichloride, to provide 2-alkyl-3-alkoxy-6-acetyl-anilines such as 2-methyl-3-methoxy-6-acetyl-aniline. The 2-alkyl-3-alkoxy-6-acetyl-anilines, such as 2-methyl-3-methoxy-6-acetyl-aniline, can be coupled to an an optionally substituted thiazole-2-carboxylic acid chloride, such as 4-isopropylthiazole-2-carbonyl chloride to provide an optionally substituted 1-acetyl-2-[(thiazol-2-yl)-carbonylamino]-3-alkyl-4-alkoxy-benzene, such as 1-acetyl-2-[(4-isopropyl-thiazol-2-yl)-carbonylamino]-3-methyl-4-methoxy-benzene. The optionally substituted 1-acetyl-2-[(thiazol-2-yl)-carbonylamino]-3-alkyl-4-alkoxy-benzene, such as 1-acetyl-2-[(4-isopropyl-thiazol-2-yl)-carbonylamino]-3-methyl-4-methoxy-benzene, can be cyclized under basic conditions, for example sodium tert-butoxide in tert-butanol, to provide an optionally substituted 2-(thiazol-2-yl)-4-hydroxy-7-alkoxy-8-alkyl-quinoline, such as 2-(4-isopropylthiazol-2-yl)-4-hydroxy-7-methoxy-8-methyl-quinoline. Finally, an optionally substituted 2-(thiazol-2-yl)-4-hydroxy-7-alkoxy-8-alkyl-quinoline, such as 2-(4-isopropylthiazol-2-yl)-4-hydroxy-7-methoxy-8-methyl-quinoline can be reacted with a chlorinating agent, for example phosphorous oxychloride, oxalyl chloride, thionyl chloride and the like, to provide an optionally substituted 2-(thiazol-2-yl)-4-chloro-7-alkoxy-8-alkyl-quinoline 2-phenyl-4-chloro-7-alkoxy-quinolines, such as 2-(4-isopropylthiazol-2-yl)-4-chloro-7-methoxy-8-methyl-quinoline.

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