Benzoxazole compounds, process for producing the same and herbicides

A herbicide containing the compound represented by the formula (I-c) or the formula (I-d) as follows:

• wherein R1 to R4 may be the same or different from each other, and each represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a haloalkyl group having 1 to 4 carbon atoms, a haloalkoxy group having 1 to 4 carbon atoms, a halogen atom, a nitro group, a cyano group, R12S(O)n, an alkoxycarbonyl group having 1 to 4 carbon atoms, or a carbonyl group, where R12 represents an alkyl group having 1 to 6 carbon atoms, and n is an integer of 0 to 2, provided that all of R1 to R4 are not simultaneously hydrogen atoms, R5′ represents an alkyl group having 1 to 6 carbon atoms, R6′ represents a hydrogen atom, a hydroxyl group, a halogen atom or an alkyl group having 1 to 4 carbon atoms, R9′ represents a hydrogen atom, a cyano group, a haloalkyl group having 1 to 4 carbon atoms, a haloalkoxy group having 1 to 4 carbon atoms, a nitro group or R12S(O)n, where R12 and n have the same meanings as defined above, R10′ represents a hydrogen atom, a halogen atom, a haloalkyl group having 1 to 4 carbon atoms or a cyano group;
• and the formula (I-d) being as follows:
• wherein R1 to R4, R5′, R6′, R9′ and R10′ have the same meanings as defined above, and
• R7′ represents a hydrogen atom, a hydroxyl group, a halogen atom or a substituted sulfonyloxy group;
• and
• a herbicidally acceptable carrier.

A process for producing a compound (I-c) represented by the following formula (I-c):

• wherein R1 to R4 may be the same or different from each other, and each represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a haloalkyl group having 1 to 4 carbon atoms, a haloalkoxy group having 1 to 4 carbon atoms, a halogen atom, a nitro group, a cyano group, R12S(O)n, an alkoxycarbonyl group having 1 to 4 carbon atoms, or a carbonyl group, where R12 represents an alkyl group having 1 to 6 carbon atoms, and n is an integer of 0 to 2, provided that all of R1 to R4 are not simultaneously hydrogen atoms, R5′ represents an alkyl group having 1 to 6 carbon atoms, R6′ represents a hydrogen atom, a hydroxyl group, a halogen atom or an alkyl group having 1 to 4 carbon atoms, R9′ represents a hydrogen atom, a cyano group, a haloalkyl group having 1 to 4 carbon atoms, a haloalkoxy group having 1 to 4 carbon atoms, a nitro group or R12S(O)n, where R12 and n have the same meanings as defined above, R10′ represents a hydrogen atom, a halogen atom, a haloalkyl group having 1 to 4 carbon atoms or a cyano group,
• or a compound (I-d) represented by the following formula (I-d):
• wherein R1 to R4, R5′, R6′, R9′ and R10′ have the same meanings as defined above, and R7′ represents a hydrogen atom, a hydroxyl group, a halogen atom or a substituted sulfonyloxy group,
• which comprises reacting, in the presence of a base or an acid catalyst in a solvent, a compound (XII) represented by the following formula(XII):
• wherein R1 to R4 have the same meanings as defined above, with a compound (XV-a) represented by the following formula (XV-a):
• wherein R5′, R6′, R9′ and R10′ have the same meanings as defined above, or a compound (XV-b) represented by the following formula (XV-b):
• wherein R5′, R6′, R7′, R9′ and R10′ have the same meanings as defined above.