Abstract: A process for producing a substituted aminoquinazolinone derivative of formula (I), characterized by reducing a substituted iminoquinazolinone derivative of formula (II) with hydrogen in the presence of a catalyst and either of a halogen compound and a sulfur compound; a substituted iminoquinazolinone derivative of formula (II?); and a pest control agent containing the derivative of formula (II?) or a salt thereof as an active ingredient and a method of using the same (in the formulae, R represents hydrogen, formyl, (C1-C6) alkyl, (C1-C6)alkoxy(C1-C3)alkyl, (C1-C6) alkylsulfonyl, optionally substituted phenylcarbonyl, etc.; R1 represents an optionally substituted, 5- or 6-membered heterocycle having one to three heteroatoms selected among oxygen, sulfur, and nitrogen; R2 represents hydrogen or (C1-C3) alkyl; X and X? may be the same or different and each represents (C1-C6) haloalkyl, (C1-C6) haloalkoxy, etc.; n is an integer of 0; and n? is an integer of 1-4).

Abstract: A process for producing a substituted aminoquinazolinone derivative represented by the formula (I), characterized by reducing a substituted iminoquinazolinone derivative represented by the formula (II) with hydrogen in the presence of a catalyst and either of a halogen compound and a sulfur compound; a substituted iminoquinazolinone derivative represented by the formula (II?), which is an intermediate in the production process; and a pest control agent containing the derivative of the formula (II?) or a salt thereof as an active ingredient and a method of using the same (in the formulae, R represents hydrogen, formyl, (C1-C6) alkyl, (C1-C6)alkoxy(C1-C3)alkyl, (C1-C6) alkylsulfonyl, optionally substituted phenylcarbonyl, etc.

Abstract: Compound of the general formula (I), which is useful as an agricultural and horticultural fungicide, an agricultural and horticultural fungicidal composition containing said compound, use of said composition for controlling plant disease, and process for the production of said compound: ##STR1## wherein ##STR2## shows a case in which R.sup.3 and R.sup.4 together form a cyclic substituent, and R.sup.1 and R.sup.4 are substituents disclosed in the specification.