SYNTHESIS OF 4-ALKYLPYRAZOLES FROM 3,5-DIAMINOPYRAZOLES

The possibility of preparing 4-alkylpyrazoles from malononitrile (thro ugh C-alkyl malononitriles and 3,5-diamino-4 alkylpyrazoles) has been explored. Although some difficulties arise in the double-deamination s tep, the method has allowed the synthesis of 4-benzyl- and 4-phenethyl -pyrazoles. New 3-halogenopyrazoles have also been prepared. The synth esis of 3,5-diamino-4-iodopyrazole is reported. This elusive compound has a C-13 NMR spectrum in which an aromatic carbon (C-4) appears at d elta 29.53