I've done exactly that in the past, when I was working for a large photographic operation. We were given a colour negative and required to make a large volume of B&W prints.
We used two methods: the first was to make an interpositive on panchromatic film, and then an internegative on ortho film. This was time consuming, and dust was a problem. So, I found that one could expose the original colour negative on to Ilford XP-2 sheet film, and then process it in an E-6 line.
The main problem with this is that the contrast will be low; you will almost certainly have to "push" the film in order to get adequate contrast. Also, the resulting negative will have a blue-ish cast to it. Some exposure and development tests are definitely in order.
Also, unless you are doing your own E-6 processing, the lab may refuse to give your film E-6 processing. Have a word with the manager or owner. They may tell you that it will throw their process out of control. It has been my experienece, with more than 27 years in theh industry, that that won't happen unless you are running an awful lot of C-41 film through an E-6 line.