摘要 |
Anti-allergic compounds of the formulae <CHEM> wherein, X is S or O; R1 and R2 is hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, aryl, aralkyl, sulfonamido, halogen, alkoxy, alkenyloxy, alkynyloxy, cyano, hydroxy, acyloxy, nitro, amino, alkylamino, alkanoylamino, carbalkoxyamino, methanesulfonyl, carboxy, carbalkoxy, trihalomethyl, or taken together, methylenedioxy; R3 and R4 is hydrogen, alkyl, alkenyl, alkynyl, aryl, acyl, aralkyl, cycloalkyl, cycloalkyl, cycloalkyl CH2-, or carbalkoxy; and Z forms a heterocyclic ring with the two carbon atoms to which it is attached; and intermediates for their preparation. |