N2-1H-BENZIMIDAZOL-2-YL-N4-PHENYL-2,4-PYRIMIDINEDIAMINES AND N2-1H-BENZIMIDAZOL-2-YL-5,6,7,8-TETRAHYDRO-N4-PHENYL-2,4-QUINAZOLINEDIAMINES AS POTENTIAL ANTIFILARIAL AGENTS

A series of N2-1H-benzimidazol-2-yl-N4-phenyl-2,4-pyrimidinediamines and N2-1H-benzimidazol-2-yl-5,6,7,8-tetrahydro-N4-phenyl-2,4-quinazolinediamines (XI) was synthesized for antifilarial evaluation. Condensation of the requisite beta-keto ester (VI) with N-cyanoguanidine afforded 2-pyrimidinylcyanamides (VIIa,b) and (5,6,7,8-tetrahydro-4-hydroxy-2-quinazolinyl)cyanamide (VIIc). Reaction of VII with a substituted o-phenylenediamine gave 2-(1H-benzimidazol-2-ylamino)-4-pyrimidinols and 2-[(5,6-dichloro-1H-benzimidazol-2-yl)amino]-5,6,7, 8-tetrahydro-4-quinazolinol (IX). Chlorination with phosphoryl chloride, followed by condensation with the appropriate substituted benzenamine, gave the desired N2-1H-benzimidazol-2-yl-N4-phenyl-2,4-pyrimidinediamines and N2-1H-benzimidazol-2-yl-5,6,7,8-tetrahydro-N4-phenyl-2,4-quinazolinediamines (XI). None of these compounds possessed antifilarial activity against Litomosoides carinii or Brugia pahangi infections in jirds.