Abstract: Certain tricyclic sulphoxide compounds each of which is substituted in the 1-,2-,3- or 4-position by a carboxyl or (5-tetrazolyl) group and each of which is optionally substituted in the 5-,6-,7- or 8-position by a second carboxyl or (5-tetrazolyl) group or a substituent selected from cyano, halogen, nitro, alkyl, alkoxy, acyl, amino, acylamino, thioalkyl, alkylsulphinyl and alkylsulphonyl, as well as salts, and optionally substituted esters and amides of the carboxyl substituted compounds and alkyl derivatives of the tetrazolyl substituted compounds, are useful for the relief or prophylaxis of allergic conditions.

Abstract: A pharmaceutical composition and method for inhibiting the symptoms of allergic conditions such as asthma or allergic rhinitis which comprises administering a compound of the formula ##STR1## where Z.sup.2 is in the 6 position, wherein Z.sup.1 and Z.sup.2 are carboxylate, a pharmaceutically acceptable carboxylate salt, alkyl carboxylate, carboxamide, N-alkyl carboxamide, or N,N,-dialkylcarboxamide where alkyl in the above has 1 to 6 carbon atoms.

Abstract: Certain acridone and xanthone compounds, each of which is 2-substituted by a carboxyl group or a salt, ester or optionally substituted amide thereof and each of which is optionally substituted in the 5-, 6-, 7- or 8-position, by a second carboxyl group, salt, ester or optionally substituted amide thereof, the substituent in the 5-, 6-, 7- or 8-position of the acridone compounds, also being selected from cyano, halogen, nitro, alkyl, alkoxy and acyl, are useful for the relief or prophylaxis of allergic conditions.

Abstract: A process for the preparation of a cyanophenol of formula (I) ##SPC1##wherein Z is a substituent in the 4- or 6-position with respect to the hydroxy group, characterized in that cyanide ions are reacted in a dipolar aprotic solvent with a nitrobenzene of formula (II) ##SPC2##wherein Z has the same value as in formula (I) and is a group, other than a nitro group, known to withdraw electrons in substitution reactions and which does not contain a proton capable of ionizing under the defined reaction conditions if such ionization would inhibit the electron-withdrawing effect of the group Z.In formula (I) and (II) the benzene ring is optionally substituted by one or more non electron-withdrawing groups, or by one or more electron-withdrawing groups provided that such electron-withdrawing groups are in positions other than the 4- and 6-positions with respect to the hydroxy group.