{TAIL ~ A method} of treating male erectile dysfunction comprising administering to a male human {HEAD ~ a pyrimidine compound} of formula I 
{ TAIL ~ A method } of treating male erectile dysfunction comprising administering to a male human { HEAD ~ a pyrimidine compound } of formula I
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH