抗ヒスタミン活性を有する三環式化合物を調製するためのプロセス

Japanese Patent JP4558942

B2

Disclosed is a process for preparing a compound having formula (I) wherein R<1> is selected from the group consisting of: alkyl, alkenyl, alkynyl, aryl, aralkyl, cycloalkyl, and cycloalkyalkyl, R<1> being optionally substituted by substituents selected from halo, -OH, alkyl, alkoxy, or -CF3, said process comprising the following steps: (a) reacting a ketone having formula (A) with a carbanion having formula (B) wherein R<1> is defined above, and R<2> and R<3> are independently selected from the group consisting of -OR and -R; wherein R is alkyl, phenyl, substituted phenyl, cycloalkyl, substituted cycloalkyl, cycloalkylalkyl, or substituted cycloalkylalkyl; (b) treating the reaction mixture from step (a) with a protonating agent to form a beta -hydroxy intermediate having formula (C) wherein R<1>, R<2> and R<3> are as defined above; and (c) thermally decomposing the beta -hydroxy intermediate to form the compound of formula (I). The compounds made by this process have antihistaminic activity, e.g., loratadine. Also disclosed is a process for preparing descarboethoxyloratadine, by carrying out the process above, and converting the product to descarboethoxyloratadine. Also disclosed are novel intermediates having formula (II) and (III) wherein R<1>, R<2> and R<3> are as defined above.

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Schering Corporation

C07D401/04; C07F9/59; C07F9/6558

JP61289087A

J. CHEM. SOC., PERKIN TRANS 1,1998年10月 7日,19,3241-3243
Journal of Organic Chemistry,1970年,35,3,777-780
Journal of the Korean Chemical Society,1996年,40,5,374-378
Tetrahedron Letters,1990年,31,19,2743-2746
Tetrahedron Letters ,1989年,30,34,4581-4584

Hidesaku Yamamoto

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