A Convenient Synthesis of New Pyrazolo[4,3-d]pyrimidines and Their Fused Heterocycles

A series of some fused heterocycles originated from pyrazolopyrimidines were synthesized using 4-amino1-methyl-3-propyl-1H-pyrazole-5-carboxamide as a starting material. The nucleophilic substitution reactions with different amino acids followed by cyclization and Suzuki-Miyaura cross-coupling reactions with different aryl boronic acids of 7-chloro-5-(4-chlorophenyl)-1-methyl-3-propyl-1H-pyrazolo[4,3-d]pyrimidine were performed. Also, the oxidative cyclization reactions of 1-(5-(4-chlorophenyl)-1-methyl-3-propyl-1H-pyrazolo[4,3-d]pyrimidin-7-yl)hydrazine with different aldehydes in the presence of diacetoxy iodobenzene are described. All the synthesized compounds were characterized by analytical and spectroscopic methods.