6-azido-1,3-dimethyl-5-formyluracil

5,7-dimethyl-2-(1-p-tolyl-vinyl)-2,7-dihydro-pyrazolo[3,4-d]pyrimidine-4,6-dione

5,7-dimethyl-2-(1-phenyl-vinyl)-2,7-dihydro-pyrazolo[3,4-d]pyrimidine-4,6-dione

2-[1-(4-chloro-phenyl)-vinyl]-5,7-dimethyl-2,7-dihydro-pyrazolo[3,4-d]pyrimidine-4,6-dione

2-[1-(4-methoxy-phenyl)-vinyl]-5,7-dimethyl-2,7-dihydro-pyrazolo[3,4-d]pyrimidine-4,6-dione