7985. Pyrimethamine

Nomenclature

CAS number: 58-14-0
5-(4-Chlorophenyl)-6-ethyl-2,4-pyrimidinediamine; 2,4-diamino-5-(p-chlorophenyl)-6-ethylpyrimidine; RP-4753; Daraprim (GSK); Malocide (Aventis).
C12H13ClN4; mol wt 248.71.
C 57.95%, H 5.27%, Cl 14.25%, N 22.53%.

Description and references

Dihydrofolate reductase inhibitor; generally used in combination with other antimicrobial agents. Prepn: P. B. Russell, G. H. Hitchings, J. Am. Chem. Soc. 73, 3763 (1951); G. H. Hitchings et al., US 2576939 (1951 to Burroughs Wellcome); W. Logemann et al., Ber. 87, 435 (1954); R. M. Jacob, US 2680740 (1954 to Rh^one-Poulenc). Review of antimicrobial activity and mechanism of action: Burchall in Antibiotics vol. 3, J. W. Corcoran, F. E. Hahn, Eds. (Springer-Verlag, New York, 1975) pp 312-320. Comprehensive description: M. A. Loutfy, H. Y. Aboul-Enein, Anal. Profiles Drug Subs. 12, 463-482 (1983). LC-MS determn in plasma: B. A. Sinnaeve et al., J. Chromatogr. A 1076, 97 (2005). Clinical evaluations in toxoplasmosis in AIDS patients: C. Leport et al., Am. J. Med. 84, 94 (1988); B. Dannemann et al., Ann. Intern. Med. 116, 33 (1992). Review of clinical experience in malaria: H. M. McIntosh et al., Ann. Trop. Med. Parasitol. 93, 265-270 (1998); C. V. Plowe et al., Br. Med. J. 328, 545 (2004).

Chemical structure

Properties

Crystals, mp 233-234° (capillary); mp 240-242° (copper block). Practically insol in water. Slightly sol in ethanol, (about 9 g/l), in dil HCl (about 5 g/l); sol in boiling ethanol (about 25 g/l). Very sparingly sol in propylene glycol and dimethylacetamide at 70°.

Derivative

Combination with sulfadoxine.

Nomenclature

CAS number: 37338-39-9
Fansidar (Roche).

Therapeutic Category

Antiprotozoal (Toxoplasma); antimalarial.

Therapeutic Category (Veterinary)

Antiprotozoal (Toxoplasma).

Keywords

Antimalarial; Antiprotozoal (Toxoplasma)