Abstract: The present invention provides a pipe tapping apparatus to couple new pipes to an existing pipe. The pipe tapping apparatus includes a base pipe, having a saddle-shaped socket part to be in close contact with the main pipe to pass a fluid therein; and a bending part coupled to the saddle-shaped socket part. The pipe tapping apparatus further includes a coupling pipe to be coupled to the sub-pipe extending to a predetermined place in which the supplied fluid is used, with a ball valve provided in the coupling pipe to control the flow of fluid passing through the coupling pipe. The pipe tapping apparatus further includes an electric heat-welding pipe to couple the coupling pipe to the base pipe. The electric heat-welding pipe has a first heating wire which is provided in the electric heat-welding pipe to weld the electric heat-welding pipe to the base pipe, and a second heating wire which is provided in the electric heat-welding pipe to integrate the coupling pipe with the electric heat-welding pipe.

Abstract: A process for producing amide derivatives represented by general formula (XV) ##STR1## or enantiomers thereof, novel intermediate compounds useful for producing these compounds, etc., and a process for producing the same, wherein each symbol is as defined in the specification. Compared with the conventional processes, the above process can be very easily effected and enables an efficient production of the compounds (XV), i.e., those involving the compounds (XVI) having an HIV protease inhibitory effect in high yields. The novel intermediates are highly advantageous as intermediates for producing not only the above compounds (XVI) but also those which are useful as an X-ray contrast medium, etc.