The A21 receptor extracelluar site and the A2 receptor extracellular site of adenosine analogues are structurally different and that binding orientations of adenosine or adenosine analogues are different at these sites and this may be used to determine their structure. Novel pyrimidine compounds are described.
This application relates to compounds of formula (I), ##STR00001## wherein R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are defined as recited in the claims, or a tautomer, salt, hydrate, or alkoxide thereof. A process for preparing such materials, pharmaceutical compositions containing them, and methods of treating a cardiovascular disorder by administering them to a patient are also disclosed and claimed.
![Pyrazolo[3,4-d]pyrimidines with adenosine-like binding affinities - US Patent 5227485 - Page 1](http://www.wikipatents.com/pyrazolo34-dpyrimidines-with-adenosine-like-binding-affinities/T/US5227485-1.jpg "Pyrazolo[3,4-d]pyrimidines with adenosine-like binding affinities - US Patent 5227485 - Page 1")
![Pyrazolo[3,4-d]pyrimidines with adenosine-like binding affinities - US Patent 5227485 - Page 2](http://www.wikipatents.com/pyrazolo34-dpyrimidines-with-adenosine-like-binding-affinities/T/US5227485-2.jpg "Pyrazolo[3,4-d]pyrimidines with adenosine-like binding affinities - US Patent 5227485 - Page 2")
![Pyrazolo[3,4-d]pyrimidines with adenosine-like binding affinities - US Patent 5227485 - Page 3](http://www.wikipatents.com/pyrazolo34-dpyrimidines-with-adenosine-like-binding-affinities/T/US5227485-3.jpg "Pyrazolo[3,4-d]pyrimidines with adenosine-like binding affinities - US Patent 5227485 - Page 3")
![Pyrazolo[3,4-d]pyrimidines with adenosine-like binding affinities - US Patent 5227485 - Page 4](http://www.wikipatents.com/pyrazolo34-dpyrimidines-with-adenosine-like-binding-affinities/T/US5227485-4.jpg "Pyrazolo[3,4-d]pyrimidines with adenosine-like binding affinities - US Patent 5227485 - Page 4")
![Pyrazolo[3,4-d]pyrimidines with adenosine-like binding affinities - US Patent 5227485 - Page 5](http://www.wikipatents.com/pyrazolo34-dpyrimidines-with-adenosine-like-binding-affinities/T/US5227485-5.jpg "Pyrazolo[3,4-d]pyrimidines with adenosine-like binding affinities - US Patent 5227485 - Page 5")
![Pyrazolo[3,4-d]pyrimidines with adenosine-like binding affinities - US Patent 5227485 - Page 6](http://www.wikipatents.com/pyrazolo34-dpyrimidines-with-adenosine-like-binding-affinities/T/US5227485-6.jpg "Pyrazolo[3,4-d]pyrimidines with adenosine-like binding affinities - US Patent 5227485 - Page 6")
