Study of 1-Methyl-3-propyl-4-aminopyrazole-5-carbonitrile

1-Methyl-3-propyl-4-aminopyrazole-5-carbonitrile was synthesized by using 1-methyl-3-propylpyrazole-5-formic as starting materials in four steps reaction including acylation, dehydration, nitrification and reduction. Then pyrazolopyrimidinone derivatives were obtained from the condensation of 1-methyl-3-propyl-4-aminopyrazole-5-carbonitrile and aldehydes. 1-Methyl-3-propyl-4-nitropyrazole-5-carbonitrile was reduced to amine in the presence of palladium-charcoal. Three intermediate products, hydroxylamine, azoxypyrazole and azopyrazole, were separated and detected with HPLC and HPLC-HRMS during the formation of amine pyrazole. Possible reduction mechanism was proposed. The structures of products were characterized by ¹H NMR, ¹³C NMR, IR spectra and MS.