Famotidine

Athanor · official

C₈H₁₅N₇O₂S₃ · 337.5 g/mol

IUPAC name: 3-[[2-(diaminomethylideneamino)-1,3-thiazol-4-yl]methylsulfanyl]-N'-sulfamoylpropanimidamide

Also called Pepcid, H2 blocker

Drugs Rings

Open in Athanor

Drawn from its SMILES with RDKit

Names and identifiers

IUPAC name: 3-[[2-(diaminomethylideneamino)-1,3-thiazol-4-yl]methylsulfanyl]-N'-sulfamoylpropanimidamide
Synonyms: Pepcid, H2 blocker, Famogard
+ 39 more
Famopsin, Famovane, Mensoma, Nevofam, Purifam, Brolin, Hacip, Gastro, Famotidine-13C3, Apogastine, Gastrodomina, Gastrosidin, Antodine, Bestidine, Blocacid, Confobos, Cuantin, Dispronil, Famocid, Famodar, Famodin, Famodine, Famonit, Famotal, Famotep, Famotin, Famowal, Fibonel, Gastridan, Gastrion, Gastrofam, Huberdina, Ingastri, Invigan, Midefam, Neocidine, Notidin, Nulceran, Nulcerin
Molecular formula: C₈H₁₅N₇O₂S₃
Empirical formula: C₈H₁₅N₇O₂S₃
Molecular weight: 337.5 g/mol
Exact mass: 337.04494
CAS number: 76824-35-6
PubChem CID: 3325
Canonical SMILES: C1=C(N=C(S1)N=C(N)N)CSCCC(=NS(=O)(=O)N)N
Isomeric SMILES: C1=C(N=C(S1)N=C(N)N)CSCCC(=NS(=O)(=O)N)N
InChI: InChI=1S/C8H15N7O2S3/c9-6(15-20(12,16)17)1-2-18-3-5-4-19-8(13-5)14-7(10)11/h4H,1-3H2,(H2,9,15)(H2,12,16,17)(H4,10,11,13,14)
InChIKey: XUFQPHANEAPEMJ-UHFFFAOYSA-N
Molfile

Names, InChI and the identifiers from PubChem, retrieved 2026-10-14.

Calculated

Heavy atoms: 20
Rings: 1
Aromatic rings: 1
Fraction sp³ carbons (Fsp3): 0.38
H-bond donors: 5 computed here · PubChem 4
H-bond acceptors: 6 computed here · PubChem 8
Rotatable bonds: 7
TPSA (Å²): 173.3 computed here · PubChem 238
Formal charge: 0
XLogP3: -0.6 PubChem
Complexity: 469 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

C28.47%
H4.48%
N29.06%
O9.48%
S28.51%

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: -0.37 Crippen (Wildman and Crippen 1999)
log S (water solubility): -1.42 ESOL (Delaney 2004), log mol/L
Synthetic accessibility: 3.27 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)

Drug-likeness: Lipinski’s rule of five

Molecular weight ≤ 500: 337.46
log P ≤ 5 (Crippen): -0.37
H-bond donors ≤ 5: 5
H-bond acceptors ≤ 10: 6

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

No GHS hazard classification was found in the sources.

Safety data sheets on the supplier’s page: LGC Standards, Thermo Fisher Scientific, Quality Control Solutions (QCS Standards).

Always read the supplier’s safety data sheet before working with it.

Spectra

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]Human Metabolome Database (HMDB) · Linked only · via PubChem · retrieved 2026-10-14
[2]SpectraBase · Linked only · via PubChem · retrieved 2026-10-14
[3]MassBank Europe · Linked only · 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.