Loperamide (C29H33ClN2O2): structure, properties and hazards

Names and identifiers

IUPAC name: 4-[4-(4-chlorophenyl)-4-hydroxypiperidin-1-yl]-N,N-dimethyl-2,2-diphenylbutanamide
Synonyms: Imodium, antidiarrhoeal, Loperamida
+ 37 more
Loperamidum, 4-[4-(4-chlorophenyl)-4-hydroxypiperidin-1-yl]-N,N-dimethyl-2,2-diphenylbutanamide, Fortasec, DTXSID6045165, 6X9OC3H4II, 4-(4-(4-chlorophenyl)-4-hydroxypiperidin-1-yl)-N,N-dimethyl-2,2-diphenylbutanamide, 4-(4-Chlorophenyl)-N,N-dimethyl-alpha,alpha-diphenyl-4-hydroxy-1-piperidinebutanamide, CHEBI:6532, DTXCID4025165, 1-Piperidinebutanamide, 4-(4-chlorophenyl)-4-hydroxy-N,N-dimethyl-alpha,alpha-diphenyl-, NSC696356, RefChem:5959, 258-416-5, Ioperamide, Maalox Anti-Diarrheal, Loperamide (INN), CHEMBL841, Loperamidum [INN-Latin], Loperamida [INN-Spanish], NCGC00015608-04, Loperacap, A1CMV, LOPERAMIDE [INN], Apo-Loperamide, Nu-Loperamide, Rho-Loperamide, Kaopectate II, PMS-Loperamide, Loperamide [INN:BAN], 1-Piperidinebutanamide, 4-(4-chlorophenyl)-4-hydroxy-N,N-dimethyl-.alpha.,.alpha.-diphenyl-, 2-methoxyethyl1-methylethyl2,6-dimethyl-4-(3-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate, Imodium A-D Caplets, 4-(p-Chlorophenyl)-4-hydroxy-N,N-dimethyl-.alpha.,.alpha.-diphenyl-1-piperidinebutyramide, 4-[4-(4-Chlorophenyl)-4-hydroxy-1-piperidinyl]-N,N-dimethyl-2,2-diphenylbutanamide, Diamide (TN), CAS-53179-11-6, EINECS 258-416-5
Molecular formula: C₂₉H₃₃ClN₂O₂
Empirical formula: C₂₉H₃₃ClN₂O₂
Molecular weight: 477 g/mol
Exact mass: 476.22306
CAS number: 53179-11-6
PubChem CID: 3955
Canonical SMILES: CN(C)C(=O)C(CCN1CCC(CC1)(C2=CC=C(C=C2)Cl)O)(C3=CC=CC=C3)C4=CC=CC=C4
Isomeric SMILES: CN(C)C(=O)C(CCN1CCC(CC1)(C2=CC=C(C=C2)Cl)O)(C3=CC=CC=C3)C4=CC=CC=C4
InChI: InChI=1S/C29H33ClN2O2/c1-31(2)27(33)29(24-9-5-3-6-10-24,25-11-7-4-8-12-25)19-22-32-20-17-28(34,18-21-32)23-13-15-26(30)16-14-23/h3-16,34H,17-22H2,1-2H3
InChIKey: RDOIQAHITMMDAJ-UHFFFAOYSA-N
Molfile

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

Calculated

Heavy atoms: 34
Rings: 4
Aromatic rings: 3
Fraction sp³ carbons (Fsp3): 0.34
H-bond donors: 1
H-bond acceptors: 3
Rotatable bonds: 7
TPSA (Å²): 43.8
Formal charge: 0
XLogP3: 5 PubChem
Complexity: 623 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

C73.02%
H6.97%
Cl7.43%
N5.87%
O6.71%

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: 5.09 Crippen (Wildman and Crippen 1999)
log S (water solubility): -5.93 ESOL (Delaney 2004), log mol/L
Synthetic accessibility: 2.55 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)

Drug-likeness: Lipinski’s rule of five

Molecular weight ≤ 500: 477.05
log P ≤ 5 (Crippen): 5.09
H-bond donors ≤ 5: 1
H-bond acceptors ≤ 10: 3

Breaks 1 of the 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: 7 company reports to ECHA. Source [1].

Acute toxicity

H301Toxic if swallowed

Precautionary statements: P264, P270, P301+P316, P321, P330, P405, P501

Storage

Keep container tightly closed in a dry and well-ventilated place. Light sensitive. (loperamide hydrochloride)[2]

Incompatibilities

Incompatible materials: Strong oxidizing agents (loperamide hydrochloride)[2]

Safety data sheets on the supplier’s page: Ambinter, InvivoChem, Pi Chemicals.

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]European Chemicals Agency (ECHA) · ECHA legal notice: reuse with acknowledgement · via PubChem · retrieved 2026-10-14
[2]Hazardous Substances Data Bank (HSDB) · Public domain (US NLM) · via PubChem · retrieved 2026-10-14
[3]Human Metabolome Database (HMDB) · Linked only · via PubChem · retrieved 2026-10-14
[4]NIST Mass Spectrometry Data Center · Linked only · via PubChem · retrieved 2026-10-14
[5]SpectraBase · Linked only · via PubChem · retrieved 2026-10-14
[6]MassBank Europe · Linked only · via PubChem · retrieved 2026-10-14
[7]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.