Compounds of formula (I), wherein R.sub.1 is as defined in the claims, exhibit COMT enzyme inhibiting activity and are thus useful as COMT inhibitors. Methods of treatment and pharmaceutical dosage forms are also disclosed.

A compound represented by formula (4) is produced by a step A of reacting a compound represented by formula (2):

##STR00001##

wherein R.sup.1 represents an ethyl group or the like, R represents a halogen atom or the like, n represents 0, 1, 2, or 3, and M represents potassium or the like, with thionyl chloride to obtain a compound represented by formula (1):

##STR00002##

a step B of reacting the compound represented by formula (1) with a compound represented by formula (5):

##STR00003##

wherein A.sup.1 represents a nitrogen atom or CH, R.sup.5 represents a trifluoromethyl group or the like, and m represents 1 or 2, to produce a compound represented by formula (3):

##STR00004##

or an acid salt thereof; and a step C of reacting the compound represented by formula (3) or an acid salt thereof in the presence of acid at 100 C. to 180 C. to obtain the compound represented by formula (4):

##STR00005##

The present invention relates to a novel process for preparing the compound 4-(cyclopropylmethoxy)-N-(3,5-di-chloro-1-oxido-4-pyridyl)-5-methoxypyridine-2-carboxamide of formula (1), in base or hydrate form or in the form of pharmaceutically acceptable salts, and also to several novel synthetic intermediates that are useful in this preparation process. ##STR00001##

The present invention provides a pest control agent, acaricide or fungicide that contains, as the active ingredient thereof, at least one type of compound selected from the aryloxyurea compounds represented by formula (V) (wherein R.sup.1 to R.sup.5 each independently represents an alkyl group or the like, X is a halogen atom or the like, n is an integer of 0 to 5, and Z is an oxygen atom or sulfur atom) or salts thereof. ##STR00001##

The present invention provides a pest control agent, acaricide or fungicide that contains, as the active ingredient thereof, at least one type of compound selected from the aryloxyurea compounds represented by formula (V) (wherein R.sup.1 to R.sup.5 each independently represents an alkyl group or the like, X is a halogen atom or the like, n is an integer of 0 to 5, and Z is an oxygen atom or sulfur atom) or salts thereof. ##STR00001##