Synthesis of 4-acetyl-5(3)-amino-3(5)-methylpyrazoles and pyrazolopyrimidines from diacetylketene N,S-acetal

Article abstract of DOI:10.1007/BF00699932

Isomeric 4-acetyl-5-amino-3-methyl- and 4-acetyl-3-amino-5-methylpyrazoles (2, 3) were formed in the reaction of hydrazones with 3-pentan-2,4-dione (1) (diacetylketene N,S-acetal).Pyrazolo<3,4-d>pyrimidines (5a,b) were synthesized by condensation of 4-acetyl-5-amino-1,3-dimethylpyrazole (2a) with amide dimethylacetals followed by treatment with ammonium acetate.The structures of the compounds obtained were confirmed by 13C and 15N NMR spectroscopy. - Key words: diacetylketene N,S-acetal; hydrazines; 4-acetyl-5(3)-aminopyrazoles; amide acetals; pyrazolo<3,4-d>pyrimidines.