O=C(NC1CCCC(C2CCCCC2)C1)C1CCN(C(=O)CCl)CC1
O=C(Nc1ccccc1N1CCC1)C1CCN(C(=O)CCl)CC1
O=C(Nc1ccccc1C1COC1)C1CCN(C(=O)CCl)CC1
SeeSAR 9.2 Inspirator, ReCore with docking, and growing in binding site, x1358, https://www.diamond.ac.uk/covid-19/for-scientists/Main-protease-structure-and-XChem.html