Processes for preparation of 5-pyrazolemercaptan derivatives and intermediates thereof.

摘要

The present invention relates to a process for preparation of 5-pyrazolemercaptan derivatives represented by the following general formula (I), which is useful for synthesis of sulfonylurea-based herbicides, and an intermediate thereof, <CHEM> wherein R<1> represents hydrogen, C1-C4 alkyl, allyl or propargyl, R<2> represents hydrogen, C1-C4 alkyl, or a phenyl group which can contain one or more substituent selected from the group consisting of halogen, nitro and methyl at an optional position, and R<3> represents hydrogen, methyl, ethyl or phenyl.