Claim analyzed

Science

“The chemical name of diclofenac is 2-[(2,6-dichlorophenyl)amino]phenylacetic acid.”

Submitted by Quiet Deer b107

True
9/10
Created: May 19, 2026
Updated: July 12, 2026

The stated name correctly identifies diclofenac's free-acid form. Authoritative references often prefer equivalent variants such as "benzeneacetic acid" or "dichloroanilino" wording, but these describe the same structure. The statement is accurate, though it is not the only standard naming form for diclofenac.

Caveats

  • Several major databases prefer alternate but equivalent names, so this is a valid chemical name rather than the uniquely preferred one in all references.
  • Drug labels often name diclofenac salts such as diclofenac sodium or diclofenac potassium, which are different forms from the free acid named here.
  • The singular phrasing "the chemical name" can mislead because compounds commonly have multiple accepted systematic and synonym forms.

Sources

Sources used in the analysis

#1
FDA 2009-01-01 | Voltaren (diclofenac sodium enteric-coated tablets) label

The FDA label states that the chemical name is 2-[(2,6-dichlorophenyl)amino] benzeneacetic acid, monosodium salt. This is the sodium salt form of diclofenac, not the free acid.

#2
National Cancer Institute diclofenac sodium - NCI Drug Dictionary

NCI identifies diclofenac sodium as having the chemical structure 2-[(2,6-dichlorophenyl)amino]benzeneacetic acid monosodium salt. It also describes it as the sodium salt form of diclofenac.

#3
NIST WebBook Diclofenac

The NIST WebBook entry for CAS Registry Number 15307-86-5 (Diclofenac) lists under "Other names": "Benzeneacetic acid, 2-[(2,6-dichlorophenyl)amino]-; Acetic acid, (o-(2,6-dichloroanilino)phenyl)-; Dichlofenac; Diclofenac acid; 2-[(2,6-Dichlorophenyl)amino]benzeneacetic acid; 2-[(2,6-Dichlorophenyl)amino]benzoic acid (diclofenac acid)." This shows that one of the recognized names for diclofenac is "2-[(2,6-Dichlorophenyl)amino]benzeneacetic acid."

#4
PubChem Diclofenac | CID 3033

PubChem gives diclofenac's IUPAC name as 2-[2-(2,6-dichloroanilino)phenyl]acetic acid and lists synonyms including 2-(2,6-dichlorophenyl)amino)benzeneacetic acid and Diclofenac free acid. The formula is C14H11Cl2NO2.

#5
NIST Diclofenac - the NIST WebBook

The NIST WebBook lists diclofenac with the synonym 2-[(2,6-Dichlorophenyl)amino]benzeneacetic acid, and the molecular formula C14H11Cl2NO2.

#6
ChemSpider Diclofenac | C14H11Cl2NO2

ChemSpider lists diclofenac as 2-((2,6-dichlorophenyl)amino)benzeneacetic acid and 2-[2-[(2,6-dichlorophenyl)amino]phenyl]acetic acid, along with the molecular formula C14H11Cl2NO2.

#7
LGC Standards 2-[2-[(2,6-Dichlorophenyl)amino]phenyl]acetic Acid (Diclofenac)

The LGC Standards Mikromol reference material entry lists the product name as "2-[2-[(2,6-Dichlorophenyl)amino]phenyl]acetic Acid (Diclofenac)" with CAS Number 15307-86-5. In the analyte data, the IUPAC name is given as "2-[2-(2,6-dichloroanilino)phenyl]acetic acid." This indicates that the formal IUPAC name used is "2-[2-(2,6-dichloroanilino)phenyl]acetic acid" rather than the benzeneacetic form, though the structure corresponds to diclofenac acid.

#8
PubChem - NIH 2025-09-15 | Diclofenac | C14H11Cl2NO2 | CID 3033 - PubChem - NIH

In the Diclofenac entry (CID 3033) on PubChem, the "IUPAC Name" field explicitly states: "2-[2-(2,6-dichloroanilino)phenyl]acetic acid." Additional synonyms include benzeneacetic acid derivatives with a 2,6-dichloroanilino/phenylamino substituent, consistent with the described chemical structure.

#9
DrugBank Diclofenac: Uses, Interactions, Mechanism of Action

DrugBank gives the IUPAC name as 2-{2-[(2,6-dichlorophenyl)amino]phenyl}acetic acid and lists the formula C14H11Cl2NO2.

#10

The PDSP Ki Database record for Diclofenac lists the compound as "2-[2-[(2,6-Dichlorophenyl)amino]phenyl]acetic Acid (Diclofenac)" and in the same header also notes the name "2-[(2,6-dichlorophenyl)amino]phenylacetic acid." This shows that diclofenac is referred to both as the phenylacetic acid derivative and with a closely related name, confirming the structural description as a 2-[(2,6-dichlorophenyl)amino]phenylacetic acid.

#11
DrugBank Diclofenac sodium

DrugBank’s entry for diclofenac sodium gives the IUPAC Name as: "sodium 2-{2-[(2,6-dichlorophenyl)amino]phenyl}acetate." This name describes the sodium salt of diclofenac, whose acid form corresponds to 2-{2-[(2,6-dichlorophenyl)amino]phenyl}acetic acid (diclofenac).

#12
PubChem 2025-09-15 | Diclofenac Potassium | C14H10Cl2KNO2 | CID 23667642 - PubChem

For Diclofenac Potassium (CID 23667642), PubChem lists the IUPAC name as: "potassium 2-[2-(2,6-dichloroanilino)phenyl]acetate." This is the potassium salt of diclofenac, where the parent acid is 2-[2-(2,6-dichloroanilino)phenyl]acetic acid.

#13
PubChem 2-{2-[(2,6-dichlorophenyl)amino]phenyl}acetic acid N-[(2E) -

The PubChem entry for the clofaziminium–diclofenac cocrystal lists as part of the IUPAC name block: "2-[2-(2,6-dichloroanilino)phenyl]acetate; 2-[2-(2,6-dichloroanilino)phenyl]acetic acid." In the components section, diclofenac is represented by the fragment "OC(=O)Cc1ccccc1Nc1c(Cl)cccc1Cl" corresponding to 2-[2-(2,6-dichloroanilino)phenyl]acetic acid. This confirms that diclofenac’s acid form is named as "2-[2-(2,6-dichloroanilino)phenyl]acetic acid" in IUPAC-style nomenclature.

#14
PubChem Diclofenac sodium | C14H10Cl2NNaO2 | CID 5018304 - PubChem

The PubChem entry for diclofenac sodium lists under "2.1.1 IUPAC Name": "sodium 2-[2-(2,6-dichloroanilino)phenyl]acetate." This is the IUPAC name for the sodium salt form of diclofenac, derived from the parent acid 2-[2-(2,6-dichloroanilino)phenyl]acetic acid.

#15
ChemSpider Diclofenac sodium | C14H10Cl2NNaO2

The ChemSpider entry for "Diclofenac sodium" (C14H10Cl2NNaO2) lists among the names and synonyms: "2-[(2,6-Dichlorophenyl)amino]benzeneacetic Acid Monosodium Salt" and "2-[(2,6-Dichlorophenyl)amino]benzeneacetic acid sodium salt." It also gives the description "benzeneacetic acid, 2-[(2,6-dichlorophenyl)amino]-, monosodium salt" and notes the RN 15307-79-6 for the sodium salt. This indicates that the sodium salt of diclofenac is systematically described as the monosodium salt of "benzeneacetic acid, 2-[(2,6-dichlorophenyl)amino]-".

#16
Cayman Chemical Diclofenac (sodium salt) (CAS 15307-79-6)

Cayman Chemical lists the formal name of diclofenac sodium salt as 2-[(2,6-dichlorophenyl)amino]-benzeneacetic acid, monosodium salt.

#17
CymitQuimica 2-[2-[(2,6-Dichlorophenyl)amino]phenyl]acetic Acid (Diclofenac)

The Cymit Quimica product page for CAS 15307-86-5 lists the compound name as "2-[2-[(2,6-Dichlorophenyl)amino]phenyl]acetic Acid (Diclofenac)." Under synonyms it includes "Diclofenac; 2-(2,6-Dichloroanilino)phenylacetic acid; 2-(2,6-Dichlorophenylamino)phenylacetic acid; 2-[(2,6-Dichlorophenyl)amino]benzeneacetic …" indicating that "2-[(2,6-Dichlorophenyl)amino]benzeneacetic" appears in synonym form associated with diclofenac acid.

#18
Wikipedia Diclofenac - Wikipedia

Wikipedia states that diclofenac's IUPAC name is [2-(2,6-Dichloroanilino)phenyl]acetic acid and explains that the name 'diclofenac' derives from the chemical name 2-(2,6-dichloranilino)phenylacetic acid.

#19
MP Biomedicals Diclofenac

MP Biomedicals’ entry for Diclofenac lists alternate names including "2-[(2,6-Dichlorophenyl)amino]-benzeneacetic acid monosodium salt" and "2-[(2,6-Dichlorophenyl)amino]benzeneacetic acid sodium salt". It further describes the substance as the monosodium salt of "benzeneacetic acid, 2-[(2,6-dichlorophenyl)amino]-". This supports that the diclofenac sodium form is named as a benzeneacetic acid derivative bearing a 2-[(2,6-dichlorophenyl)amino] substituent.

#20
Mayo Clinic Diclofenac (oral route) - Side effects & dosage

Mayo Clinic describes diclofenac as a nonsteroidal anti-inflammatory drug used for pain and arthritis symptoms, but does not provide the chemical name.

#21
ChemicalBook 2-[2-[(2,6-dichlorophenyl)amino]phenyl]acetic acid;2-pyrrolidin-1 ...

ChemicalBook’s safety data sheet for a compound titled "2-[2-[(2,6-dichlorophenyl)amino]phenyl]acetic acid;2-pyrrolidin-1-ylethanol" lists the "Chemical name" at the top as "2-[2-[(2,6-dichlorophenyl)amino]phenyl]acetic acid;2-pyrrolidin-1-ylethanol" and describes common names and synonyms including 2-[2-[(2,6-dichlorophenyl)amino]phenyl]acetic acid. This shows another commercial source identifying diclofenac’s acid component using the "2-[2-[(2,6-dichlorophenyl)amino]phenyl]acetic acid" nomenclature.

#22
LLM Background Knowledge Equivalence of phenylacetic acid and benzeneacetic acid terminology

From background chemical nomenclature knowledge: the fragment "phenylacetic acid" denotes a phenyl group attached to a –CH2–COOH unit, while "benzeneacetic acid" is an equivalent description; both are acceptable variants referring to the same structural motif in IUPAC-derived names.

Full Analysis

Debate

Two AI advocates debated this claim using the research gathered.

Argument for

P
Proponent Argues TRUE

The chemical name of diclofenac is indeed 2-[(2,6-dichlorophenyl)amino]phenylacetic acid, as explicitly confirmed by the PDSP Ki Database (UNC) which lists this exact name in its compound record (Source 10). This nomenclature is chemically equivalent to the "benzeneacetic acid" variants cited by other authorities, since "phenylacetic acid" and "benzeneacetic acid" are interchangeable terms describing the exact same structural motif (Source 22).

O
Opponent Rebuttal

The Proponent's argument hinges on a single tertiary database header (Source 10, PDSP Ki Database) while disregarding that the highest-authority chemical-name statements in the brief identify diclofenac products as the monosodium salt “2-[(2,6-dichlorophenyl)amino]benzeneacetic acid, monosodium salt,” not the free-acid phrasing asserted in the motion (Source 1, FDA; Source 2, NCI). Invoking “interchangeability” via background knowledge (Source 22) is a category error that conflates structural equivalence with what counts as the chemical name used by primary reference databases, which standardize diclofenac's parent name differently (e.g., “2-[2-(2,6-dichloroanilino)phenyl]acetic acid” / “2-[(2,6-dichlorophenyl)amino]benzeneacetic acid”) rather than the motion's exact string (Source 8, PubChem; Source 3, NIST WebBook).

Argument against

O
Opponent Argues FALSE

The motion is false because the highest-authority regulatory and reference sources do not give diclofenac's chemical name as “2-[(2,6-dichlorophenyl)amino]phenylacetic acid,” but instead as benzeneacetic/acetate forms (e.g., FDA lists “2-[(2,6-dichlorophenyl)amino] benzeneacetic acid, monosodium salt” for the drug product, not the free acid name in the motion) (Source 1, FDA; Source 2, NCI). Even for the free acid, PubChem and NIST standardize the parent as “2-[2-(2,6-dichloroanilino)phenyl]acetic acid” / “2-[(2,6-dichlorophenyl)amino]benzeneacetic acid,” so the motion's specific “phenylacetic acid” wording is not the chemical name these primary databases use (Source 8, PubChem; Source 3, NIST WebBook).

P
Proponent Rebuttal

The Opponent's argument relies on a false distinction between "phenylacetic acid" and "benzeneacetic acid," which are chemically equivalent, interchangeable terms describing the exact same structural motif (Source 22). Furthermore, the Opponent ignores that authoritative databases explicitly recognize this exact phrasing, with the PDSP Ki Database listing "2-[(2,6-dichlorophenyl)amino]phenylacetic acid" (Source 10) and CymitQuimica listing "2-(2,6-dichlorophenylamino)phenylacetic acid" as a synonym for the free acid (Source 17).


Panel Review

3 specialized AI experts evaluated the evidence and arguments.

Reviewer 1 — The Logic Examiner

Focus: Inferential Soundness & Fallacies
Mostly True
8/10

Multiple reference databases explicitly list diclofenac (free acid, CAS 15307-86-5) under synonymous systematic names that are chemically equivalent to the claim's wording, including “2-[(2,6-dichlorophenyl)amino]benzeneacetic acid” (NIST, Sources 3 and 5) and IUPAC-style variants “2-[2-(2,6-dichloroanilino)phenyl]acetic acid” / “2-{2-[(2,6-dichlorophenyl)amino]phenyl}acetic acid” (PubChem/DrugBank, Sources 8 and 9), while at least one database also uses essentially the claim's exact phrasing in its record header (Source 10). Because “benzeneacetic acid” and “phenylacetic acid” denote the same structural motif and the remaining bracket/brace/anilino-vs-phenylamino differences are standard nomenclature variants for the same structure, the evidence supports that the claim's name is a correct chemical name for diclofenac even if some regulatory labels focus on salt forms (Sources 1–2).

Logical fallacies

The opponent risks an equivocation by treating “not the standardized preferred name in some databases” as if it implied “not a correct chemical name,” which does not logically follow.The proponent risks an appeal to a weaker authority by leaning heavily on a single tertiary database string (Source 10) when stronger sources mainly support the claim via synonymy rather than the exact phrasing.
Confidence: 7/10

Reviewer 2 — The Source Auditor

Focus: Source Reliability & Independence
Mostly False
3/10

The claim states the chemical name of diclofenac is '2-[(2,6-dichlorophenyl)amino]phenylacetic acid.' The most authoritative sources (FDA Source 1, NCI Source 2, NIST Sources 3 and 5, PubChem Sources 4 and 8) consistently use either 'benzeneacetic acid' variants or '2-[2-(2,6-dichloroanilino)phenyl]acetic acid' as the preferred/IUPAC name for diclofenac's free acid form — not the exact 'phenylacetic acid' phrasing in the claim. The PDSP Ki Database (Source 10) does list '2-[(2,6-dichlorophenyl)amino]phenylacetic acid' as a name, and Source 22 (LLM background knowledge) argues 'phenylacetic acid' and 'benzeneacetic acid' are interchangeable. However, 'phenylacetic acid' and 'benzeneacetic acid' are indeed chemically equivalent synonyms for the same structural motif (PhCH2COOH), so the claim's name describes the correct structure. The issue is whether this exact string constitutes 'the chemical name': primary authoritative databases (FDA, NCI, NIST, PubChem) do not use this exact phrasing as their primary or IUPAC name, though it appears as a recognized synonym in some sources. The claim is partially correct in that it describes the right compound with a recognized synonym, but the most authoritative sources use different preferred nomenclature, and the claim presents this as 'the' chemical name rather than 'a' chemical name. This makes the claim mostly false as a definitive statement of the primary chemical name, though not entirely wrong as a structural description.

Weakest sources

Source 22 is an LLM background knowledge entry with no external citation, publication date, or peer review, making it the least authoritative source in the pool.Source 10 (PDSP Ki Database) is a tertiary pharmacological database that lists the claimed name only in a header field, not as a primary IUPAC designation, limiting its weight as evidence for the claim.Source 20 (Mayo Clinic) does not provide any chemical name for diclofenac and is therefore irrelevant to evaluating this specific claim.
Confidence: 8/10

Reviewer 3 — The Precision Analyst

Focus: Claim Precision & Quantitative Accuracy
True
10/10

The claim's chemical name is a valid and recognized synonym for diclofenac, as confirmed by the PDSP Ki Database (Source 10) and CymitQuimica (Source 17). While IUPAC and primary databases often standardize on 'benzeneacetic acid' or 'dichloroanilino' variants, 'phenylacetic acid' and 'benzeneacetic acid' are chemically equivalent, interchangeable terms representing the exact same structure (Source 22).

Confidence: 10/10

Panel summary

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The claim is
True
9/10
Confidence: 8/10 Spread: 7 pts

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True · Lenz Score 9/10 Lenz
“The chemical name of diclofenac is 2-[(2,6-dichlorophenyl)amino]phenylacetic acid.”
22 sources · 3-panel audit · Verified May 2026
See full report on Lenz →