pyrimethamine

CHEBI:8673 ·resolve ·ANTIPROTOZOAL ·EXACT SEEDED

An aminopyrimidine that is pyrimidine-2,4-diamine which is substituted at position 5 by a p-chlorophenyl group and at position 6 by an ethyl group. It is a folic acid antagonist used as an antimalarial or with a sulfonamide to treat toxoplasmosis. — ChEBI

Machine-generated and unreviewed. Identity, structure and cross-references come straight from ChEBI's and CARD's own data; no curator has signed off on this record yet.

Classification

antibiotic without defined classificationARO:3000003

Strictly broader compounds or drug classes this molecule belongs to.

Label unavailable CHEBI:38338
Label unavailable CHEBI:83403
antibiotic without defined classification ARO:3000003

Chemical structure

Computed structure properties
Molecular formula	C12H13ClN4
Charge	0
Average mass	248.717 Da
Monoisotopic mass	248.08287 Da
Source	ChEBI
InChIKey	WKSAUQYGYAYLPV-UHFFFAOYSA-N

SMILES

CCc1nc(N)nc(N)c1-c1ccc(Cl)cc1

InChI

InChI=1S/C12H13ClN4/c1-2-9-10(11(14)17-12(15)16-9)7-3-5-8(13)6-4-7/h3-6H,2H2,1H3,(H4,14,15,16,17)

Also called

pirimetamina (INN)— chebi
pyrimethaminum (INN)— chebi
pyriméthamine (INN)— chebi
5-(4-chlorophenyl)-6-ethylpyrimidine-2,4-diamine (EXACT_SYNONYM)— chebi
2,4-Diamino-5-(4-chlorophenyl)-6-ethylpyrimidine (EXACT_SYNONYM)— chebi
2,4-Diamino-5-(p-chlorophenyl)-6-ethylpyrimidine (EXACT_SYNONYM)— chebi
2,4-Diamino-5-chlorophenyl-6-ethylpyrimidine (EXACT_SYNONYM)— chebi
5-(4'-Chlorophenyl)-2,4-diamino-6-ethylpyrimidine (EXACT_SYNONYM)— chebi
5-(4-Chlorophenyl)-6-ethyl-2,4-diaminopyrimidine (EXACT_SYNONYM)— chebi
5-(4-Chlorophenyl)-6-ethyl-2,4-pyrimidinediamine (EXACT_SYNONYM)— chebi
CD (EXACT_SYNONYM)— chebi
Chloridine (EXACT_SYNONYM)— chebi
Chloridyn (EXACT_SYNONYM)— chebi
Diaminopyritamin (EXACT_SYNONYM)— chebi
Ethylpyrimidine (EXACT_SYNONYM)— chebi
Primethamine (EXACT_SYNONYM)— chebi
chloridin (EXACT_SYNONYM)— chebi
diaminopyritamin (EXACT_SYNONYM)— chebi
pirimecidan (EXACT_SYNONYM)— chebi
pirimetamin (EXACT_SYNONYM)— chebi
pyrimethamin (EXACT_SYNONYM)— chebi

Cross-references

Identifiers for this same structure in other resources. An accession that lands on two different structures in this corpus is withheld from both rather than shown here, since it names at most one of them.

Drug registries

Identifiers that name a drug rather than a structure. One of these can cover a parent compound, its salts and its stereoisomers, which this corpus keeps as separate records, so it is not an equivalence of structure.

Patents and articles

Documents about this compound. A patent covers a class and an article covers a topic; neither identifies a structure.

wikipedia.en:Pyrimethamine

Activity roles

Every antimicrobial role a source asserts for this compound — the unreduced evidence behind its antimicrobial_class.

antiprotozoal drug CHEBI:35820
antimalarial CHEBI:38068

Source concepts

Every upstream concept that resolved to this record. The merge is the product: this is what shows ChEBI and CARD are describing the same structure.

Upstream concepts merged into this record
Source	Native ID	Label	Minted CURIE	Version
ARO	`ARO:3009163`	pyrimethamine	`antibioticmech:aro-e7e60b9586`	2026-08-30
CHEBI	`CHEBI:8673`	pyrimethamine	`antibioticmech:chebi-389df716d8`	2026-08-30

Mechanism summary

Mode of action: FOLATE_PATHWAY_INHIBITION host shared target — Assigned from ChEBI role CHEBI:50683 (EC 1.5.1.3 (dihydrofolate reductase) inhibitor). ChEBI asserts the role on the compound. The target it names is one the host has too, so the mechanism is true but is not evidence of selectivity — see mode_of_action_target_scope. Not a curator's mechanistic review.
Clinical status: APPROVED

Resistance mechanisms

2 source-backed resistance determinants or associations, with ARO grounding where reported. Grouped by reported mechanism type.

ANTIBIOTIC_TARGET_ALTERATION 2

ANTIBIOTIC_TARGET_ALTERATION
Determinant	ARO ID	Organism	Gene families	Evidence
Pneumocystis jerovecii dhfr with mutations associated with resistance to Trimethoprim sulfamethoxazole combined with Pyrimethamine atovaquone	ARO:3009290	not organism-specific	—	ARO:3009290 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3009163 (pyrimethamine); database assertion, not a primary citation.)
Pneumocystis jerovecii dhfr with mutations associated with resistance to pyrimethamine-sulfadoxine	ARO:3009285	not organism-specific	—	ARO:3009285 (CARD/ARO asserts confers_resistance_to_antibiotic ARO:3009163 (pyrimethamine); database assertion, not a primary citation.)

Curation history

SEEDED_FROM_SOURCES 2026-08-30 · seed_from_sources
Seeded from data/raw/ inventories (ARO, CHEBI)
RESEEDED_FROM_SOURCES 2026-08-30 · seed_from_sources
Re-seeded from updated data/raw/ inventories
RESEEDED_FROM_SOURCES 2026-08-30 · seed_from_sources
Re-seeded from updated data/raw/ inventories
RESEEDED_FROM_SOURCES 2026-08-31 · seed_from_sources
Re-seeded from updated data/raw/ inventories
RESEEDED_FROM_SOURCES 2026-08-31 · seed_from_sources
Re-seeded from updated data/raw/ inventories
RESEEDED_FROM_SOURCES 2026-09-10 · seed_from_sources
Re-seeded from updated data/raw/ inventories

Provenance

Seeded by scripts/seed_from_sources.py from the committed inventories in data/raw/. View the record (YAML).

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