HETEROCYCLIC COMPOUNDS

of the disclosure: A novel heterocyclic compound capable of lowering the uric acid levels in plasma and urine having the formula (I): (I) wherein R1 and R2 are independently hydrogen, lower alkyl, phenyl or substituted phenyl, or R1 and R2 may form a fourto eight-membered carbon ring together with the carbon atom to which they are attached; R3 is hydrogen or lower alkyl; R4 is one or two radicals selected from a group consisting of hydrogen, halogen, nitro, lower alkyl, phenyl, substituted phenyl, -OR5 and -SO2NR6R6'; R5 is hydrogen, lower alkyl, phenyl-substituted lower alkyl, carboxymethyl or ester thereof, hydroxyethyl or ether thereof, or allyl; R6 and R6' are independently hydrogen or lower alkyl; R7 is hydrogen or a pharmaceutically active ester-forming group; A is a straight or branched hydrocarbon radical having one to five carbon atoms; B is halogen, oxygen, or dithiolane; Y is oxygen, sulfur nitrogen or substituted nitrogen; Z is oxygen, nitrogen or substituted nitrogen; dotted line represents the presence or absence of a single bond.