Studies in fluorinated 1,3-diketones and related compounds. Part XVII. Synthesis and spectroscopic studies of some new 5-alkyl-3-fluoroaryl-1-pentafluoroaryl-pyrazoles and 2-amino-6-alkyl(perfluoroalkyl)-4-aryl pyrimidines

Abstract

Six new 3-(4′-fluorophenyl)-1,5-trisubstituted pyrazoles have been synthesized from the appropriate fluorinated 1,3-diketones and pentafluorophenylhydrazine in the presence of absolute ethanol and hydrochloric acid, viz., 1-pentafluorophenyl-3-(4′-fluorophenyl)-5- methylpyrazole, 1-pentafluorophenyl-3-(4′-fluorophenyl)-5-trifluoromethylpyrazole, 5- ethyl-1-pentafluorophenyl-3-(4′-fluorophenyl) pyrazole, 5-(pentafluoroethyl)-1-pentafluorophenyl-3-(4′-fluorophenyl) pyrazole, 1-pentafluorophenyl-3-(4′-fluorophenyl) 5-n-propylpyrazole and 5-(heptafluoropropyl)-1-pentafluorophenyl-3-(4′-fluorophenyl) pyrazole. In addition, six new 2-amino-4-(4′-fluorophenyl)-6-alkyl(perfluoroalkyl)-trisubstituted pyrimidines have been prepared from the same diketones and guanidine carbonate in the presence of hydrochloric acid using absolute ethanol as a solvent, viz., 2-amino- 4(4′-fluorophenyl)-6-methylpyrimidine, 2-amino-4(4′-fluorophenyl)-6-trifluoromethylpyrimidine, 2-amino-6-ethyl-4(4′-fluorophenyl)pyrimidine, 2-amino-6-pentafluoroethyl-4-(4′-fluorophenyl)pyrimidine, 2-amino-4-(4′-fluorophenyl)-6-n-propylpyrimidine and 2- amino-6-(heptafluoropropyl)-4-(4′-fluorophenyl)pyrimidine. All new fluorinated pyrazoles as well as pyrimidines have been characterized by elemental analyses as well as spectral studies.