Us. Pathak et al., SYNTHESIS OF SOME PYRAZOLO[3,4-D]PYRIMIDINES, Indian journal of chemistry. Sect. B: organic chemistry, including medical chemistry, 33(8), 1994, pp. 734-737
Some bstituted-arylpyrazolo[3,4-d]pyrimidine-4(5H)-ones are synthesize
d by transformation of thyl-1-phenyl-1H-pyrazolo[3,4-d][1,3]oxazin-4-o
nes and also from 5-amino-4-carbethoxy-1-phenyl pyrazole.