Abstract: 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, ##STR1## wherein R.sup.1 represents hydrogen, C.sub.1 -C.sub.4 alkyl, allyl or propargyl,R.sup.2 represents hydrogen, C.sub.1 -C.sub.4 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, andR.sup.3 represents hydrogen, methyl, ethyl or phenyl.

Abstract: 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, ##STR1## wherein R.sup.1 represents hydrogen, C.sub.1 -C.sub.4 alkyl, allyl or propargyl,R.sup.2 represents hydrogen, C.sub.1 -C.sub.4 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, andR.sup.3 represents hydrogen, methyl, ethyl or phenyl.

Abstract: 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, ##STR1## wherein R.sup.1 represents hydrogen, C.sub.1 -C.sub.4 alkyl, allyl or propargyl,R.sup.2 represents hydrogen, C.sub.1 -C.sub.4 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, andR.sup.3 represents hydrogen, methyl, ethyl or phenyl.

Abstract: 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 sulfonyl-urea-based herbicides, and an intermediate thereof, ##STR1## wherein R.sup.1 represents hydrogen, C.sub.1 -C.sub.4 alkyl, allyl or propargyl,R.sup.2 represents hydrogen, C.sub.1 -C.sub.4 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, andR.sup.3 represents hydrogen, methyl, ethyl or phenyl.

Abstract: A parallel phone detection circuit is described, the function of which is to enable a phone call to be transferred from a first telephone set to a second telephone set. The detection circuit maintains the first telephone set connected to the telephone line until the handset of the second telephone set has been taken off-hook, and then disconnects the first telephone set. The circuit operates by detecting the line current from the telephone line and produces the reference value for comparison purposes related to that line current.