O=C(CCl)N1CCC(C(=O)N2CCNC2)CC1
O=C(CCl)N1CCC(C(=O)N2CCCO2)CC1
O=C(CCl)N1CCC(C(=O)N2CCOC2)CC1
O=C(CCl)N1CCC(C(=O)N2CCSC2)CC1
O=C(CCl)N1CCC(C(=O)N2CCNO2)CC1
O=C(CCl)N1CCC(C(=O)N2CNCO2)CC1
O=C(CCl)N1CCC(C(=O)N2CNOC2)CC1
O=C(CCl)N1CCC(C(=O)N2CONO2)CC1
O=C(CCl)N1CCC(C(=O)N2CSCO2)CC1
O=C(CCl)N1CCN(C(=O)N2CCCC2)CC1
NC(=O)N1CCN(C(=O)CCl)CC1
CNC(=O)N1CCN(C(=O)CCl)CC1
O=C(CCl)N1CCN(C(=O)N2CCCCCC2)CC1
NC(=O)C1CCN(C(=O)CCl)CN1
NC(=O)C1CCN(C(=O)CCl)OC1
NC(=O)C1CCN(C(=O)CCl)CO1
NC(=O)C1CCN(C(=O)CCl)CS1
PCM-0102655 and PCM-0102584 modified, https://www.diamond.ac.uk/covid-19/for-scientists/Main-protease-structure-and-XChem.html