| Ritlecitinib nitrosamine impurity 9 | NA | Ax-17607 |
| Ritlecitinib nitrosamine impurity 8 | NA | Ax-17606 |
| Ritlecitinib nitrosamine impurity 7 | NA | Ax-17605 |
| Ritlecitinib impurity 6 | NA | Ax-17604 |
| Ritlecitinib nitrosamine impurity 6 | NA | Ax-17603 |
| Ritlecitinib impurity 5 | NA | Ax-17602 |
| Ritlecitinib nitrosamine impurity 5 | NA | Ax-17601 |
| Ritlecitinib impurity 4 | 1792184-37-2 | Ax-17600 |
| Ritlecitinib impurity 3 | NA | Ax-17599 |
| Ritlecitinib nitrosamine impurity 4 | NA | Ax-17598 |