Methotrexate impurity 51
Impurity reference standard · Methotrexate
- CAS number
- —
- InChIKey
- AFMFNSBFLSSZOZ-NRFANRHFSA-N
- Molecular formula
- C21H23N9O6
- Molecular weight
- 497.46
- Exact mass
- 497.1771 Da
About Methotrexate impurity 51
Methotrexate impurity 51 is a specified impurity of Methotrexate. It has no single publicly registered CAS number, so it is defined by the structure and molecular formula below.
The compound is characterised by its molecular formula C21H23N9O6 and a molecular weight of 497.46, with the two-dimensional structure shown above. Because it shares the Methotrexate scaffold, it is typically used to track process-related and degradation impurities of Methotrexate during method development, forced degradation and stability studies.
Computed from the structure, the compound has a monoisotopic mass of 497.1771 Da, a calculated LogP of 1.05, a topological polar surface area of 231.18 Ų. It presents 4 hydrogen-bond donors and 12 acceptors. The structure carries 1 defined stereocentre, which is relevant wherever a stereochemically defined standard is required. These values are commonly used to anticipate chromatographic retention and to plan ionisation conditions during method development.
Each pack ships with a certificate of analysis together with the supporting analytical data — HNMR, MS and HPLC or GC traces — so the material can be released straight into your own QC workflow.
Available from stock in milligram to gram quantities; larger or custom synthesis requirements are quoted on request.
Calculated properties
Derived from the two-dimensional structure above using RDKit. Computed values describe the parent structure and are provided as a reference for method development — they are not measured data.
- LogP (Crippen)
- 1.05
- Topological polar surface area
- 231.18 Ų
- Hydrogen bond donors
- 4
- Hydrogen bond acceptors
- 12
- Rotatable bonds
- 10
- Heavy atoms
- 36
- Rings
- 3
- Defined stereocentres
- 1
- Elemental composition
- C 50.70% · H 4.66% · N 25.34% · O 19.30%
Frequently asked questions
Does Methotrexate impurity 51 come with a certificate of analysis?
Yes. Every pack ships with a certificate of analysis plus the supporting analytical data — HNMR, MS and HPLC or GC traces.
How is Methotrexate impurity 51 uniquely identified?
The InChIKey AFMFNSBFLSSZOZ-NRFANRHFSA-N identifies the structure unambiguously, so it can be matched against your own registry or a public database.
Is a structure file available for Methotrexate impurity 51?
Yes. The two-dimensional structure is drawn on this page from the SMILES record, and the SMILES or a molfile can be supplied on request.
What pack sizes are available for Methotrexate impurity 51?
Standard packs run from milligram to gram quantities and ship from stock. Larger or custom synthesis requirements are quoted on request.
Other Methotrexate impurities
The same parent compound, neighbouring impurity numbers.
Need this standard, or a related one?
Send the compound name, CAS number or a structure file — we confirm availability, pack size and lead time, usually within one business day.