A compound having a molecular weight of 3000 or less and a partial structure represented by Formula (X) is provided:

##STR00001##

In Formula (X), a ring W.sup.1 represents a ring structure having at least one double bond as a constituent element of the ring and having no aromaticity; and R.sup.3 represents a heterocyclic group, a halogen atom, a nitro group, a cyano group, a hydroxy group, a thiol group, a carboxy group, —SF.sub.5, —SF.sub.3, —SO.sub.3H, —SO.sub.2H, an aliphatic hydrocarbon group having 1 to 25 carbon atoms which may have a substituent, or an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent.

A compound having a molecular weight of 3000 or less and a partial structure represented by Formula (X) is provided:

##STR00001##

In Formula (X), a ring W.sup.1 represents a ring structure having at least one double bond as a constituent element of the ring and having no aromaticity; and R.sup.3 represents a heterocyclic group, a halogen atom, a nitro group, a cyano group, a hydroxy group, a thiol group, a carboxy group, —SF.sub.5, —SF.sub.3, —SO.sub.3H, —SO.sub.2H, an aliphatic hydrocarbon group having 1 to 25 carbon atoms which may have a substituent, or an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent.

The present invention provides a process for the preparation of clethodim by reacting 5-[2-(ethylthio)propyl]-2-(1-oxopropyl)-1,3-cyclohexanedione with O-(3-chloro-2-propen-1-yl)hydroxylamine in the absence of a solvent. A continuous flow process for preparing clethodim is also provided.

The present invention provides a process for the preparation of clethodim by reacting 5-[2-(ethylthio)propyl]-2-(1-oxopropyl)-1,3-cyclohexanedione with O-(3-chloro-2-propen-1-yl)hydroxylamine in the absence of a solvent. A continuous flow process for preparing clethodim is also provided.