Aromatic carboxylic amide derivatives

Abstract

Novel aromatic carboxylic amides of the general formula: ##STR1## wherein each of R 1 and R 2 is a hydrogen atom or an alkyl group having 1-4 carbon atoms, R 3 and R 4 are hydrogen atoms or together form another chemical bond, each X is a hydroxyl group, a halogen atom, an alkyl group having 1-4 carbon atoms and an alkoxy group containing 1-4 carbon atoms, and n is an integer of 1-3 with the proviso that when .[.Xs.]. .Iadd.X's .Iaddend.are alkyl or alkoxy groups, they may be connected together to form a ring, as well as pharmaceutically acceptable salts thereof. These compounds possess a strong antiallergenic action and are thus useful for treatment of asthma, hay fever, .[.anticaria.]. .Iadd.urticaria .Iaddend.and atopic dermatitis. The above aromatic carboxylic amides can be prepared by reacting a reactive functional derivative of the general formula: ##STR2## where R 1 , R 2 , R 3 , R 4 , X and n have the same meanings given above, with an aminobenzoic acid of the formula: ##STR3## and, if desired, converting the resulting amide into the corresponding salts.

What is claimed is: .[.1. A compound selected from the group consisting of an aromatic carboxylic amide derivative of the formula:.]. ##STR12## .[.and therapeutically acceptable salts thereof, in which R 1  and R 2  are each a hydrogennatom or an alkyl group having 1-4 carbon atoms, R 3  and R 4  are each a hydrogen atom or together form another chemical bond, each X is a hydroxyl group, a halogen atom, an alkyl group having 1-4 carbon atoms and an alkoxy group having 1-4 carbon atoms, and n is an integer of 1-3, provided that when two X's are said alkyl or alkoxy groups, the alkyl groups thereof may be connected together 
     
        into an alkylene group..]. .[.2.  A compound of claim 1 selected from the group consisting of a nucleus-substituted cinnamic amide of the general formula:.]. ##STR13## .[.wherein R 1 , R 2 , X and n have the same meanings as given 
     
     
        above, and therapeutically acceptable salts thereof..]. .[.3.  A compound of claim 2 wherein both R 1  and R 2  are hydrogen atoms..]. .[.4. A compound of claim 2 wherein at least one of R 1  and R 2  is an alkyl group having 1-4 carbon atoms..]. .[.5. A compound of claim 1 selected from the group consisting of a nucleus-substituted phenylpropionamide of the general formula:.]. ##STR14## ps .[.wherein R 1 , R 2 , X and n have the same meanings as given 
     
     
        above, and therapeutically acceptable salts thereof..]. .[.6.  A compound of claim 5 wherein both R 1  and R 2  are hydrogen atoms..]. .[.7. A compound of claim 5 wherein at least one of R 1  and R 2  is an 
     
     
        alkyl group having 1-4 carbon atoms..]. .Iadd.8.  A compound comprising N-(3',4'-dimethoxycinnamoyl)-anthranilic acid. .Iaddend. .Iadd.9. A compound comprising N-(3',4'-dimethoxy-β-methylcinnamoyl)-anthranilic acid. .Iaddend. .Iadd.10. A compound comprising N-(3'-methoxy-4'-n-propoxycinnamoyl)-anthranilic acid. .Iaddend.