CC(C)N(C)C(=O)N1CCN(C(=O)CCl)CC1
CCNC(=O)N1CCN(C(=O)CCl)CC1
CNC(=O)C1CCN(C(=O)CF)CC1
CNC(=O)C1CCN(C(=O)CS(C)(=O)=O)CC1
CNC(=O)N(C)CCN(C)C(=O)CCl
CC(C)c1coc(N2CCN(C(=O)CCl)CC2)n1
O=C(CCl)N1CCN(c2ncccn2)CC1
CC(C)c1coc(N(C)CCN(C)C(=O)CCl)n1
piperizine is a bioisostere of piperidine. Can also act as a an additional point for HB interaction in the protein. Simple aliphatic chain instead of cyclic piperidine may provide more flexibility to the molecular structure and catch additional HB interaction with the amino acid of the protein. Some isostere of amide such as oxazole or pyrimidine can be tried. Chloro acetyl group could possible react with thiols in the amino acid, then isostere for chloro such as fluoro or sulfone can be tried.