Chemotherapeutic agents, XXI: Synthesis of Pi-deficient pyrimidines as leishmanicides

Synthesis of 5-cyano-6-(3-pyridyl)-2-thiouracil (1) has been described from 3-pyridinecarboxaldehyde, thiourea, and ethyl cyanoacetate. Alkylation of 1 with mono- and dihaloalkanes under different conditions, provided 2a,b, 3a,b, and 4a-i. Halogenation of 4g with POCl3 yielded 5 which underwent nucleophilic substitution with amines to give 6a-g. Fusion of 4a with aromatic and heterocyclic amines at 160 degrees C gave the substitution products 7a-c. Some of the compounds were screened for antileishmanial activity but only one of them (6d) demonstrated very significant activity.