Acyclic analogues of pyrazofurin: syntheses and antiviral evaluation.

Acyclic analogues of pyrazofurin, including 4-hydroxy-3(5)-[( 2-hydroxy-1-(hydroxymethyl)-ethoxy]methyl)-1H-pyrazole-5 (3)-carboxamide (36) and 4-hydroxy-3(5)-[(2-hydroxyethoxy)methyl]-1H-pyrazole-5(3)-carboxamide (27), that possess the side chains of ganciclovir and acyclovir, respectively, were prepared by heating methyl 4-acetoxy-1-acetyl-3-bromomethyl-1H-pyrazole-5-carboxylate (15) and sodium acetate in the requisite alcohols or, for 36, with the sodium alkoxide in dry tetrahydrofuran. These analogues have no antiviral activity, except 4-hydroxy-3(5)-[(3-hydroxypropoxy)methyl]-1H-pyrazole-5(3)-carboxamide (28), which exhibited slight activity against human cytomegalovirus.