Synthesis and biological evaluation of novel urea and thiourea derivatives of valaciclovir
Series of novel urea and thiourea derivatives of valaciclovir were efficiently synthesized in high yields and their antiviral activity was evaluated. (S)-2-[(2-amino-6-oxo-6,9-dihydro-3H-purin-9-yl)methoxy]ethyl 2-amino-3-methylbutanoate (valaciclovir) (1