Thiadiazole derivative, process for producing it and agricultural and

Abstract

Disclosed is (a) 1,2,5-thiadiazole derivatives represented by the following formulae [I] or [III]: ##STR1## wherein X and Y are the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group having from 1 to 6 carbon atoms, an alkoxy group having from 1 to 4 carbon atoms, a nitro group, a trifluoromethyl group, a carboxyl group, an alkoxycarbonyl group having from 2 to 5 carbon atoms, a naphthyl group or a tetrahydronaphthyl group; and A represents an alkyl group having from 1 to 6 carbon atoms, --C(.dbd.O)OR.sup.1, --C(.dbd.O)NR.sup.2 R.sup.3, a phenyl group which may be substituted by at least one of an alkyl group having from 1 to 6 carbon atoms and an alkoxy group having from 1 to 4 carbon atoms, --CHR.sup.4 C(.dbd.O)R.sup.5 or --C(.dbd.O)R.sup.6, in which R.sup.1 represents an alkyl group having from 1 to 6 carbon atoms, R.sup.2 and R.sup.3 are the same or different and each represents a hydrogen atom or an alkyl group having from 1 to 6 carbon atoms, R.sup.4 represents a hydrogen atom or an alkyl group having from 1 to 4 carbon atoms, R.sup.5 represents an alkoxy group having from 1 to 4 carbon atoms or an amino group which may be substituted by at least one of an alkyl group having from 1 to 4 carbon atoms and a phenyl group which may be substituted by at least one halogen atom, and R.sup.6 represents an alkyl group having from 1 to 6 carbon atoms, (b) a process for producing the compound represented by formula [I] and (c) an agricultural and horticultural fungicide comprising the compound represented by formula [III].