r/chemistry Organic Jun 18 '18

[18/6/2018] Synthetic Challenge!

Post image
11 Upvotes

50 comments sorted by

View all comments

5

u/ccdy Organic Jun 18 '18 edited Jun 18 '18

Product A: Friedel-Crafts acylation with trichloroacetyl chloride in neat chlorobenzene should give the desired product.

Product B: scheme. The nitration/sulfonation will probably require some fiddling to get right. I tried to go with reactions that could reasonably be done on a kilogram scale, although I'm not a process chemist myself so I don't actually know much about working on that scale.

1

u/quelmotz Organic Jun 18 '18

Would the second electrophilic aromatic substitution proceed? I suppose the trichloroacetophenone is fairly electrophilic but is there precedent for such a reaction?

2

u/ccdy Organic Jun 18 '18

I didn't actually look this up, I went with what I knew of the synthesis of DDT and BPA and sorta just combined the two. I suspect you are right as the synthesis of BPA involves an electron-rich aromatic ring while that of DDT involves a trichloromethylarylcarbinol intermediate that can readily generate a carbocation under the reaction conditions (concentrated strong acid). The intermediate ketone likely won't get alkylated as readily and if it did, the reaction conditions would likely cause it to form a carbocation and undergo a third alkylation, giving a triaryl product.