| 摘要 |
The invention relates to compounds of formula I ( I ) wherein X represents an oxygen or sulphur atom or a group of formula -NH-, -NAlk- (in which the substituent Alk represents a C1-6 alkyl group) or -NH-?-; and R1 and R2, which may be the same or different, each represents a hydrogen atom or a phenyl or naphthyl group or, together with the carbon atoms to which they are attached, represent a phenyl group, which phenyl group may optionally be substituted by a C1-6 alkyl, C1-6 alkoxy or C1-6 alkylthio group, by one or more halogen atoms, by a nitro group, by a trifluoromethyl group, or by a group of formula -CH2-?O-Alk (in which the substituent Alk represents a C1-6 alkyl group), and to pharmaceutically acceptable addition salts thereof. These compounds and their salts are useful in the treatment of allergic asthmatic conditions and bronchitis having allergic origin. |
