Piroxicam
Athanor · official
C15H13N3O4S · 331.3 g/mol
IUPAC name: 4-hydroxy-2-methyl-1,1-dioxo-N-pyridin-2-yl-1lambda6,2-benzothiazine-3-carboxamide
Also called Feldene, NSAID, oxicam
DangerToxic if swallowed · May damage fertility or the unborn child · Suspected of damaging fertility or the unborn child · Causes damage to organs through prolonged or repeated exposureNames and identifiers
- IUPAC name
- 4-hydroxy-2-methyl-1,1-dioxo-N-pyridin-2-yl-1lambda6,2-benzothiazine-3-carboxamide
- Synonyms
- Feldene, NSAID, oxicam
+ 37 more
Piroxicamum, Pyroxycam, Roxicam, BAXO, Piroftal, CP-16171, Larapam, CP 16171, 2H-1,2-Benzothiazine-3-carboxamide, 4-hydroxy-2-methyl-N-2-pyridinyl-, 1,1-dioxide, CHF 1251, DTXSID5021170, 13T4O6VMAM, NSC-666076, CHEBI:8249, CP-16,171, 4-Hydroxy-2-methyl-N-(2-pyridyl)-2H-1,2-benzothiazin-3-caboxyamid-1,1-dioxid, NSC666076, 4-hydroxy-2-methyl-1,1-dioxo-N-pyridin-2-yl-1lambda6,2-benzothiazine-3-carboxamide, 4-hydroxy-2-methyl-N-(pyridin-2-yl)-2H-1,2-benzothiazine-3-carboxamide 1,1-dioxide, DTXCID401170, CP16171, Flamatrol, Kentene, Feldene p, 4-hydroxy-2-methyl-1,1-dioxo-N-(pyridin-2-yl)-2H-1$l^(6),2-benzothiazine-3-carboxamide, 4-hydroxy-2-methyl-1,1-dioxo-N-(pyridin-2-yl)-2H-1$l^{6},2-benzothiazine-3-carboxamide, Piroflam 10, Piroflam 20, Feldene 20, Pirozip 10, Pirozip 20, RefChem:6147, M01AC01, M02AA07, S01BC06, 4-Hydroxy-2-methyl-N-2-pyridinyl-2H-1,2-benzothiazine-3-carboximide-1,1-dioxide, 252-974-3
- Molecular formula
- C15H13N3O4S
- Empirical formula
- C15H13N3O4S
- Molecular weight
- 331.3 g/mol
- Exact mass
- 331.06268
- CAS number
- 36322-90-4
- PubChem CID
- 54676228
- Canonical SMILES
- CN1C(=C(C2=CC=CC=C2S1(=O)=O)O)C(=O)NC3=CC=CC=N3
- Isomeric SMILES
- CN1C(=C(C2=CC=CC=C2S1(=O)=O)O)C(=O)NC3=CC=CC=N3
- InChI
- InChI=1S/C15H13N3O4S/c1-18-13(15(20)17-12-8-4-5-9-16-12)14(19)10-6-2-3-7-11(10)23(18,21)22/h2-9,19H,1H3,(H,16,17,20)
- InChIKey
- QYSPLQLAKJAUJT-UHFFFAOYSA-N
- Molfile
Names, InChI and the identifiers from PubChem, retrieved 2026-10-14.
Calculated
- Heavy atoms
- 23
- Rings
- 3
- Aromatic rings
- 2
- Fraction sp³ carbons (Fsp3)
- 0.07
- H-bond donors
- 2
- H-bond acceptors
- 5 computed here · PubChem 6
- Rotatable bonds
- 2
- TPSA (Ų)
- 99.6 computed here · PubChem 108
- Formal charge
- 0
- XLogP3
- 3.1 PubChem
- Complexity
- 611 PubChem
- Stereocenters
- None
- Double-bond geometry
- None specified
- Point group
- C1 of one 3D conformer with its hydrogens, by Athanor’s engine (as in the app)
Elemental analysis
- C54.37%
- H3.95%
- N12.68%
- O19.31%
- S9.68%
Isotope pattern
Each peak is a nominal mass with its abundance-weighted exact mass, as a percentage of the tallest, from IUPAC natural isotope abundances.
Computed from the structure with RDKit 2026.09 when this page was built, beside PubChem's own computed values from its record; where the two differ, both are shown.
Predicted
- log P
- 1.58 Crippen (Wildman and Crippen 1999)
- log S (water solubility)
- -3.14 ESOL (Delaney 2004), log mol/L
- Synthetic accessibility
- 2.44 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)
Drug-likeness: Lipinski’s rule of five
- Molecular weight ≤ 500: 331.35
- log P ≤ 5 (Crippen): 1.58
- H-bond donors ≤ 5: 2
- H-bond acceptors ≤ 10: 5
Passes all four rules.
¹³C NMR shifts, predicted
Predictions, not measurements; each names its method. A measured log P, where a source reports one, is under Physical properties.
Safety
Danger
Most widely reported: 205 company reports to ECHA. Source [1].
- Acute toxicity
- Health hazard
- H301Toxic if swallowed (99% of reports)
- H360May damage fertility or the unborn child (16.6% of reports)
- H361Suspected of damaging fertility or the unborn child (17.6% of reports)
- H372Causes damage to organs through prolonged or repeated exposure (34.6% of reports)
Precautionary statements: P203, P260, P264, P270, P280, P301+P316, P318, P319, P321, P330, P405, P501
Safety data sheets on the supplier’s page: LGC Standards, Enamine, 001Chemical.
Always read the supplier’s safety data sheet before working with it.
Spectra
- 1H NMRSpectraBase
- 13C NMRSpectraBase (Varian XL-100)
- GC-MSNIST Mass Spectrometry Data Center · NIST Mass Spectrometry Data Center · NIST Mass Spectrometry Data Center · SpectraBase (GC/MS)
- MS-MSHuman Metabolome Database (HMDB) (LC-ESI-qTof · Positive) · Human Metabolome Database (HMDB) (LC-ESI-qTof · Positive) · Human Metabolome Database (HMDB) (LC-ESI-QQ · negative) · Human Metabolome Database (HMDB) (LC-ESI-QQ · negative) · Human Metabolome Database (HMDB) (Positive) · Human Metabolome Database (HMDB) (Negative)
- LC-MSMassBank Europe (Exploris 480 Orbitrap (Thermo Scientific) · LC-ESI-QFT · POSITIVE) · MassBank Europe (Exploris 480 Orbitrap (Thermo Scientific) · LC-ESI-QFT · NEGATIVE) · MassBank Europe (TripleTOF 5600 SCIEX · LC-ESI-QTOF · POSITIVE) · MassBank Europe (TripleTOF 5600 SCIEX · LC-ESI-QTOF · POSITIVE) · MassBank Europe (TripleTOF 5600 SCIEX · LC-ESI-QTOF · POSITIVE) · MassBank Europe (TripleTOF 5600 SCIEX · LC-ESI-QTOF · POSITIVE)
- ATR-IRSpectraBase (Bio-Rad FTS · ATR-Neat (DuraSamplIR II) ground)
- RamanSpectraBase (FT-Raman)
Experimental spectra held by these sources; each link opens the source's own record.
Literature
Reading PubChem, OpenAlex and GSRS…
Bioactivity
Reading ChEMBL…
References
- [1]European Chemicals Agency (ECHA) · ECHA legal notice: reuse with acknowledgement · via PubChem · retrieved 2026-10-14
- [2]SpectraBase · Linked only · via PubChem · retrieved 2026-10-14
- [3]NIST Mass Spectrometry Data Center · Linked only · via PubChem · retrieved 2026-10-14
- [4]Human Metabolome Database (HMDB) · Linked only · via PubChem · retrieved 2026-10-14
- [5]MassBank Europe · Linked only · via PubChem · retrieved 2026-10-14
- [6]MassBank of North America (MoNA) · CC BY 4.0 · via PubChem · retrieved 2026-10-14
- ·Calculated values: computed by Athanor with RDKit 2026.09 from the structure.
- ·Literature on PubChem
Data last updated 2026-10-14.