Disclosed are compounds of Formulae 1, 1a, 1b and 2, wherein R1, R1a, R1b, R2, R3 and R4 are as defined in the disclosure.Also disclosed are compositions containing the compounds of Formulae 1, 1a and 1b, and methods for controlling a parasitic nematode comprising contacting the parasitic nematode or its environment with a biologically effective amount of a compound or composition of Formulae 1, 1a, 1b and 2.所揭示者係式1、1a、1b、及2之化合物，其中R1、R1a、R1b、R2、R3、及R4係如本揭露中所定義。亦揭示者係含有式1、1a、及1b之化合物的組成物及防治寄生性線蟲之方法，該方法包含以生物有效量的式1、1a、1b、及2之化合物或組成物接觸寄生性線蟲或其環境。
