摘要:
A compounds represented by the formula ##STR1## wherein X represents a fluorine atom,W represents an oxygen atom, sulfur atom or group --OCH.sub.2 --,Z.sup.1 and Z .sup.2 each represent a nitrogen atom or group CH, but when Z.sup.1 is a nitrogen atom, Z.sup.2 represents a nitrogen atom or group CH and when Z.sup.1 is a group CH, Z.sup.2 represents a nitrogen atom,R.sup.1 and R.sup.2 each independently represent either a hydrogen atom, halogen atom or mono- or dilower alkyl-substituted amino, or a lower alkyl, lower alkoxy or lower alkylthio each of which may be substituted with a halogen atom,R.sup.3 and R.sup.4 form together with the carbon atoms to which they bind respectively a 5- to 8-membered carbon ring.