COC(=O)C1C(=O)C[C@@H](Cc2cccc(Cl)c2)O[C@H]1c1cccnc1
COC(=O)C1C(=O)C[C@H](Cc2cccc(Cl)c2)O[C@H]1c1cccnc1
COC(=O)C1C(=O)C[C@@H](Cc2ccc3ccc(S(N)(=O)=O)cc3c2)O[C@H]1c1cccnc1
COC(=O)C1C(=O)C[C@H](Cc2ccc3ccc(S(N)(=O)=O)cc3c2)O[C@H]1c1cccnc1
Using a 2,6 tetrahydropyran core to join fragments in place of a piperazine. Using an ester instead of an alpha chloro amide as the covalent warhead as this type of core is more common with an ester in the 3 position. Cis or trans stereochemistry in the 2 and 6 positions will make a difference for reactivity. These submissions are meant to be racemic.
Fragalysis snapshot: https://fragalysis.diamond.ac.uk/viewer/react/snapshot/95a6097f-7be1-4ad1-808c-b959f06f6929