Chihoko Iijima

Studies on pyrazolo[3,4-d]pyrimidine derivatives. XVIII, Facile preparation of 1H-pyrazolo[3,4-d]pyrimidin-4[5H]-ones

Reaction of 5-amino-1-phenyl-1H-pyrrazole-4-carboxamide with various ethyl alcanoates in the presence of sodium ethoxide in ethanol gave 1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4(5H)-one and its 6-substituted derivatives . Similar treatment of 5-amino-1-methyl-1H-pyrazole-4-carboxamide gave the 1-methyl-1H-pyrazolo[3,4-d]-pyrimidin-4(5H)-ones

Preparation of heteroarenecarbonitriles by reaction of heteroarene N-oxides with trimethylsilyl cyanide in the presence of DBU

Several heteroarenecarbonitriles were prepared from the corresponding heteroarene N-oxides by treatment with trimethylsilyl cyanide (TMSCN) in the presence of a base in tetrahydrofuran (THF). 1,8-Diazabicyclo [5.4.0]-7-undecene (DBU) was found to be an effective base for the cyanation