| 摘要 |
1394584 Heterocyclic substituted xanthone-2- carboxylic acid compounds SYNTEX (USA) Inc 12 July 1972 ]17 May 1972] 32540/72 Heading C2C The invention comprises compounds of the formula wherein R is H or C 1 -C 5 alkyl, and Y is -O- or -S-; and non-toxic esters, amides and salts thereof. They may be obtained by (1) treating a compound of the formula wherein R<SP>1</SP> is C 1 -C 5 alkyl, with aα-chloroaldehyde orα-chloroketone in the presence of alkali metal hydride to give the corresponding compound of the Formula (7) wherein R is hydrogen or C 1 -C 5 alkyl and R<SP>1</SP> is as above defined; and (2) cyclizing a compound of Formula (7) with acid optionally followed by hydrolysis to give the corresponding 7-(3-furyl)- xanthone-2-carboxylic acid or the alkyl esters thereof; or (3) cyclizing a compound of Formula (7) with phosphorus pentasulphide optionally followed by hydrolysis to give the corresponding 7 - (3 - thienyl) - xanthone - 2 - carboxylic acid or the alkyl esters thereof; and (4) optionally converting a product of step (2) or (3) to its non-toxic ester, amide or salt. Examples are given for the production of the compounds. Pharmaceutical compositions comprise the compounds of Formula A above which may be administered orally, topically, parenterally or by inhalation, in conventional forms optionally together with other pharmaceutical agents. They are useful for inhibiting the effects of allergic reactions, also as smooth muscle relaxants and as vasodilators. The starting compounds of Formula (6) above are prepared by the process which comprises condensing p-allylphenol with a 1,3-dicarboalkoxy-4-halobenzene in the presence of cuprous oxide to give the corresponding 1,3-dicarboalkoxy - 4 - (p - allylphenyloxy) - benzene, base hydrolysing the latter to give the corresponding 1,3 - dicarboxy - 4 - (p - allylphenyloxy)- benzene, cyclizing the latter to give the corresponding 7 - allylxanthone - 2 - carboxylic acid, esterifying the latter to the acid alkyl ester thereof, and oxidizing the latter.
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